Formstack GET submission array

Question

I have this piece of code to get a simple submission from Formstack

<?php 

    include 'formstackAPI.php';
    $formstack = new FormstackApi('3b86536d709f1c9eeef7a368ac087309');
    $formId = 4222971;  
    $response = $formstack->getSubmissions($formId, $encryptionPassword = '',
        $minTime = '', $maxTime = '', $searchFieldIds = array(),
        $searchFieldValues = array(), $pageNumber = 1, $perPage = 1, $sort = 'DESC',
        $data = false, $expandData = false);
    print_r($response);
?>

That shows me on the screen this:

array(1) { 
    [0]=> object(stdClass)#2 (8) { 
        ["id"]=> string(9) "789936126" 
        ["timestamp"]=> string(19) "2021-04-08 18:38:03" 
        ["user_agent"]=> string(115) "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36" 
        ["remote_addr"]=> string(13) "200.93.50.239" 
        ["payment_status"]=> string(0) "" 
        ["latitude"]=> string(15) "10.631699562073" 
        ["longitude"]=> string(16) "-71.640602111816" 
        ["read"]=> string(1) "0" 
        } 
    }

My question is how can I go through this array so that it only print the ["id"] on the screen?