ListLocations.php

<?php
require_once('./connect-php-sdk-master/autoload.php');

// Configure OAuth2 access token for authorization: oauth2
SquareConnect\Configuration::getDefaultConfiguration()->setAccessToken('YOUR_ACCESS_TOKEN');

$api_instance = new SquareConnect\Api\LocationsApi();

try {
    $result = $api_instance->listLocations();
    print_r($result);
} catch (Exception $e) {
    echo 'Exception when calling LocationsApi->listLocations: ', $e->getMessage(), PHP_EOL;
}
?>