Modify plugin <?php get_header?> function without editing core files

Hello!

I'm developing my own theme for an e-learning purpose, and I'm using LearnPress.

The thing is, users need to get a different header when they are logged in. Ok, i've already done this change on the whole theme, but the <?php get_header()?> function on the theme layouts for single, archive, etc are overwriting my changes.

I need to overwrite the function <?php get_header()?> without editing and hardcoding plugin core files, how can I do it?

I just need to say "make that" <?php get_header()?> get this one:

<?php

function logged_users_header() {

if ( is_user_logged_in() ) { get_header('logged'); } else { get_header(); }

}

?>

I've already inserted this snippet on my functions.php: it worked on the theme pages, not on the plugin pages

Somebody could help me?

I'm trying this - it seems to be right, but is not working...

<?php

function logged_users_header() {

if ( is_user_logged_in() && is_page_template( 'archive-course.php' 'content-course.php' 'content-single-course.php' ) ) { get_header('logged'); } else { get_header(); }

}

?>