//You can use OBJECT or null <-null worked for me
/*
* RETURNS: the post array
* post_name: is the name of the post you are looking for
* OBJECT: accepts results of WP_posts or get_posts (i.e. $posts)
* if you don't have and OBJECT just use null instead
* post_type: the name of your post type (i.e. 'page' or 'post'
* additional information https://developer.wordpress.org/reference/functions/get_page_by_title/
*
* ALSO get_page_by_path ('slug', OBJECT, 'post_type')
*/
$post = get_page_by_title( 'post_name' , OBJECT, 'post_type' );
echo $post->ID;