Adding Author URL to Nav Menu via Shortcode

I’m looking to add the Author URL to the Nav Menu via a shortcode.

Here’s the shortcode I registered:

add_shortcode( 'author_url', function() {     return get_author_posts_url( get_current_user_id() ); } ); 

After registering the shortcode, I tried using this plugin to add it to the nav menu: https://wordpress.org/plugins/shortcode-in-menus/

However, the shortcode output is https//mysite.local on my localhost

Notice how it’s lacking the ‘:’ after the https.

What’s going on, and how can I fix this?

Thanks!