Once you’ve installed and activated the plugin…
Now all you should do is add this code to your functions.php (you can also use a plugin such as Snippets to mange this code):
function acf_mapbox_api( $api ) {
$api['key'] = 'XXXX'; // Please obtain an access token from your Mapbox account and replace the dummy value
return $api;
}
add_filter( 'acf/fields/mapbox/api', 'acf_mapbox_api' );
And that’s all!
If you don’t add this key to your functions.php file then you may see the following error message:
Please set the Mapbox access token and make sure to change the ACF field name.