possible problem with function add_post_info

I’m seeing the code:
This will cost you %s. to add a new post. You may buy some bulk package as function add_post_info but it doesn’t appear anywhere that I’ve seen.
I have payments turned on but force pack purchase off.
I have packages.
When and where is this notice supposed to appear?

Thank you!

https://www.ads-software.com/plugins/wp-user-frontend/