custom plugin templates

 // Use custom template pages in a WordPress plugin
 
function my_cpt_templates( $template_path ){
	
	// Change template for CPT single pages
	if( is_singular('my_cpt') ){
		$template_path = plugin_dir_path( __FILE__ ) . 'templates/single-cpt.php';
	}
	
	// Change template for CPT archive pages for a certain taxonomy
	if( is_post_type_archive( 'my_cpt' ) ){
		$template_path = plugin_dir_path( __FILE__ ) . 'templates/archive-cpt.php';
	}
	
	return $template_path;
}

add_filter( 'template_include', 'my_cpt_templates', 1 );