Can I get the RSS of the top 10 popular posts with this plugin?

The plugin doesn’t support a custom RSS feed right now.

This link teaches you how to create a custom RSS feed.
https://www.wpbeginner.com/wp-tutorials/how-to-create-custom-rss-feeds-in-wordpress/

You can fetch the top posts using this code. It will give you the IDs of the posts.

$top_posts = tptn_pop_posts( 'posts_only=1&limit=100' );
$top_posts_array = wp_list_pluck( $top_posts, 'postnumber' );