Set Google Maps key for ACF and ACF PRO

example.php

<?php
// Add this code to plugin or theme


// Authorize API for project:
// see https://console.developers.google.com/apis/api/places_backend?project=_

const GOOGLE_API_KEY = 'the-API-key';

// ACF
add_filter('acf/fields/google_map/api', function ($value) {
  return array(
    'libraries' => 'places',
    'key'       => GOOGLE_API_KEY
  );
});

// ACF PRO
function my_acf_init() {
  acf_update_setting('google_api_key', GOOGLE_API_KEY);
}
add_action('acf/init', 'my_acf_init');