$cpapi=https://{USER}:{PASS}@{SERVER_IP}:2083/3rdparty/installatron/index.cgi?     # cpanel
#$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/themes \
    -H 'X-HTTP-Method-Override: GET' \
    -H 'Accept: application/json'

{
    "status": 200,
    "result": true,
    "message": "The task is complete.\n",
    "total_count": 1,
    "has_more": false,
    "data": [
        {
            "id": "twentytwentyfour",
            "activated": true,
            "autoup": "none",
            "version": "3.4",
            "name": "Twenty Twenty-Four",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
        {
            "id": "twentytwentyfive",
            "activated": true,
            "autoup": "none",
            "version": "1.2",
            "name": "Twenty Twenty-Five",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
    ]
}

{
    "status": 200,
    "result": true,
    "message": "The task is complete.\n",
    "total_count": 1,
    "has_more": false,
    "data": [
        {
            "id": "twentytwentyfour",
            "activated": true,
            "autoup": "none",
            "version": "3.4",
            "name": "Twenty Twenty-Four",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
        {
            "id": "twentytwentyfive",
            "activated": true,
            "autoup": "none",
            "version": "1.2",
            "name": "Twenty Twenty-Five",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
    ]
}

<?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/themes",
    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": 1,
    "has_more": false,
    "data": [
        {
            "id": "twentytwentyfour",
            "activated": true,
            "autoup": "none",
            "version": "3.4",
            "name": "Twenty Twenty-Four",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
        {
            "id": "twentytwentyfive",
            "activated": true,
            "autoup": "none",
            "version": "1.2",
            "name": "Twenty Twenty-Five",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
    ]
}

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

{
    "status": 200,
    "result": true,
    "message": "The task is complete.\n",
    "total_count": 1,
    "has_more": false,
    "data": [
        {
            "id": "twentytwentyfour",
            "activated": true,
            "autoup": "none",
            "version": "3.4",
            "name": "Twenty Twenty-Four",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
        {
            "id": "twentytwentyfive",
            "activated": true,
            "autoup": "none",
            "version": "1.2",
            "name": "Twenty Twenty-Five",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
    ]
}

{
    "status": 200,
    "result": true,
    "message": "The task is complete.\n",
    "total_count": 1,
    "has_more": false,
    "data": [
        {
            "id": "twentytwentyfour",
            "activated": true,
            "autoup": "none",
            "version": "3.4",
            "name": "Twenty Twenty-Four",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
        {
            "id": "twentytwentyfive",
            "activated": true,
            "autoup": "none",
            "version": "1.2",
            "name": "Twenty Twenty-Five",
            "description": null,
            "author": "the WordPress team",
            "version_available": null
        },
    ]
}