Using My Library (Custom Template) in Custom Content Type post

I’m looking into inc/helpers.php and need some devlopement help.

Assummed I have a custom content type called ‘outstanding’,
and I want to include a template called ‘myfooter’ in footer area.
Do we have any hook to do this?

function include_template_to_my_footer( ) {

	if ( is_singular( 'outstanding' ) ) {
		//Do something
	}

	// Retrun something
}
add_filter( /*Put a hook here*/, 'include_template_to_my_footer' );