pgmb_communicate_with_api.php

<?php

function pgmb_do_something_with_api() {

	global $post_to_google_my_business;
	if(!$post_to_google_my_business->is_loaded()){
		return;
	}

	$container = $post_to_google_my_business->get_container();

	if(!$container){
		return;
	}
	
	$api = $container['google_my_business_api'];

	$location_id = 'locations/5083214136172243061';

	$localPost = new \PGMB\Google\LocalPost('en', 'post text here', 'STANDARD');
  
	$api->create_post($location_id, $localPost);

}
add_action( 'init', 'pgmb_do_something_with_api' );