<?php

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => 'https://beta-api.solo-crm.com/mc/form',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => '',
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 0,
    CURLOPT_FOLLOWLOCATION => true,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_POSTFIELDS => [
        'name' => 'John Smith',
        'email' => 'test@test.net',
        'phone' => '+14091453225',
        'address' => 'Pasadena, Lower Peters Canyon, Irvine, Orange County, USA',
        'geolocation' => '[]' // То, что возвращает сервис https://locationiq.com, в виде json-строки
    ],
]);

$response = curl_exec($curl);

curl_close($curl);
echo $response;