Create a page template from plugin, sometimes we need to add a page template from our own plugin, this code will help to create.

index.php

<?php

function custom_template_include($template) {
    if (is_page('test')) { // your desiger page
        $new_template = IC_CORE_PATH . '/templates/custom-template.php'; // your desier file 
        if (file_exists($new_template)) {
            return $new_template;
        }
    }

    return $template;
}
add_filter('template_include', 'custom_template_include');