$cpapi=https://{USER}:{PASS}@{SERVER_IP}:2083/3rdparty/installatron/index.cgi?     # cpanel
#$cpapi=https://{USER}:{PASS}@{SERVER_IP}:2087/3rdparty/installatron/index.cgi?    # whm
#$cpapi=https://{USER}:{PASS}@{SERVER_IP}:2222/CMD_PLUGINS/installatron/index.raw? # directadmin

curl -X POST $cpapi/installs/1234567890abcdefghij12345/plugins \
    -H 'X-HTTP-Method-Override: GET' \
    -H 'Accept: application/json'

{
    "status": 200,
    "result": true,
    "message": "The task is complete.\n",
    "total_count": 2,
    "has_more": false,
    "data": [
        {
            "id": "akismet",
            "activated": true,
            "autoup": "none",
            "version": "5.4.3",
            "name": "Akismet Anti-spam: Spam Protection",
            "description": "Used by millions, Akismet is quite possibly the best way in the world to <strong>protect your blog from spam</strong>. Akismet Anti-spam keeps your site protected even while you sleep. To get started: activate the Akismet plugin and then go to your Akismet Settings page to set up your API key.",
            "author": "Automattic - Anti-spam Team",
            "version_available": "5.4.4"
        },
        {
            "id": "limit-login-attempts-reloaded",
            "activated": true,
            "autoup": "none",
            "version": "2.3.4",
            "name": "Limit Login Attempts Reloaded",
            "description": "Block excessive login attempts and protect your site against brute force attacks. Simple, yet powerful tools to improve site performance.",
            "author": "Limit Login Attempts Reloaded",
            "version_available": "2.3.4"
        }
    ]
}

{
    "status": 200,
    "result": true,
    "message": "The task is complete.\n",
    "total_count": 2,
    "has_more": false,
    "data": [
        {
            "id": "akismet",
            "activated": true,
            "autoup": "none",
            "version": "5.4.3",
            "name": "Akismet Anti-spam: Spam Protection",
            "description": "Used by millions, Akismet is quite possibly the best way in the world to <strong>protect your blog from spam</strong>. Akismet Anti-spam keeps your site protected even while you sleep. To get started: activate the Akismet plugin and then go to your Akismet Settings page to set up your API key.",
            "author": "Automattic - Anti-spam Team",
            "version_available": "5.4.4"
        },
        {
            "id": "limit-login-attempts-reloaded",
            "activated": true,
            "autoup": "none",
            "version": "2.3.4",
            "name": "Limit Login Attempts Reloaded",
            "description": "Block excessive login attempts and protect your site against brute force attacks. Simple, yet powerful tools to improve site performance.",
            "author": "Limit Login Attempts Reloaded",
            "version_available": "2.3.4"
        }
    ]
}

<?php

$cpapi   = 'https://{USER}:{PASS}@{SERVER_IP}:2083/3rdparty/installatron/index.cgi?';    // cpanel
//$cpapi = 'https://{USER}:{PASS}@{SERVER_IP}:2087/3rdparty/installatron/index.cgi?';    // whm
//$cpapi = 'https://{USER}:{PASS}@{SERVER_IP}:2222/CMD_PLUGINS/installatron/index.raw?'; // directadmin

$ch = curl_init();
curl_setopt_array($ch, [
    CURLOPT_CUSTOMREQUEST => "POST",
    CURLOPT_URL => "$cpapi/installs/1234567890abcdefghij12345/plugins",
    CURLOPT_HTTPHEADER => [
        "X-HTTP-Method-Override: GET",
        "Accept: application/json"
    ],
    CURLOPT_RETURNTRANSFER => true
]);
if (( $response = curl_exec($ch) )=== false )
{
    trigger_error(curl_error($ch));
}
curl_close($ch);
var_export(json_decode($response, true));

?>
 

{
    "status": 200,
    "result": true,
    "message": "The task is complete.\n",
    "total_count": 2,
    "has_more": false,
    "data": [
        {
            "id": "akismet",
            "activated": true,
            "autoup": "none",
            "version": "5.4.3",
            "name": "Akismet Anti-spam: Spam Protection",
            "description": "Used by millions, Akismet is quite possibly the best way in the world to <strong>protect your blog from spam</strong>. Akismet Anti-spam keeps your site protected even while you sleep. To get started: activate the Akismet plugin and then go to your Akismet Settings page to set up your API key.",
            "author": "Automattic - Anti-spam Team",
            "version_available": "5.4.4"
        },
        {
            "id": "limit-login-attempts-reloaded",
            "activated": true,
            "autoup": "none",
            "version": "2.3.4",
            "name": "Limit Login Attempts Reloaded",
            "description": "Block excessive login attempts and protect your site against brute force attacks. Simple, yet powerful tools to improve site performance.",
            "author": "Limit Login Attempts Reloaded",
            "version_available": "2.3.4"
        }
    ]
}

/usr/local/installatron/installatron \
    --GET /installs/1234567890abcdefghij12345/plugins

{
    "status": 200,
    "result": true,
    "message": "The task is complete.\n",
    "total_count": 2,
    "has_more": false,
    "data": [
        {
            "id": "akismet",
            "activated": true,
            "autoup": "none",
            "version": "5.4.3",
            "name": "Akismet Anti-spam: Spam Protection",
            "description": "Used by millions, Akismet is quite possibly the best way in the world to <strong>protect your blog from spam</strong>. Akismet Anti-spam keeps your site protected even while you sleep. To get started: activate the Akismet plugin and then go to your Akismet Settings page to set up your API key.",
            "author": "Automattic - Anti-spam Team",
            "version_available": "5.4.4"
        },
        {
            "id": "limit-login-attempts-reloaded",
            "activated": true,
            "autoup": "none",
            "version": "2.3.4",
            "name": "Limit Login Attempts Reloaded",
            "description": "Block excessive login attempts and protect your site against brute force attacks. Simple, yet powerful tools to improve site performance.",
            "author": "Limit Login Attempts Reloaded",
            "version_available": "2.3.4"
        }
    ]
}

{
    "status": 200,
    "result": true,
    "message": "The task is complete.\n",
    "total_count": 2,
    "has_more": false,
    "data": [
        {
            "id": "akismet",
            "activated": true,
            "autoup": "none",
            "version": "5.4.3",
            "name": "Akismet Anti-spam: Spam Protection",
            "description": "Used by millions, Akismet is quite possibly the best way in the world to <strong>protect your blog from spam</strong>. Akismet Anti-spam keeps your site protected even while you sleep. To get started: activate the Akismet plugin and then go to your Akismet Settings page to set up your API key.",
            "author": "Automattic - Anti-spam Team",
            "version_available": "5.4.4"
        },
        {
            "id": "limit-login-attempts-reloaded",
            "activated": true,
            "autoup": "none",
            "version": "2.3.4",
            "name": "Limit Login Attempts Reloaded",
            "description": "Block excessive login attempts and protect your site against brute force attacks. Simple, yet powerful tools to improve site performance.",
            "author": "Limit Login Attempts Reloaded",
            "version_available": "2.3.4"
        }
    ]
}