[נפתר] I added a new language but it doesn't appear

Background of the issue:
I added a new translation language, English, to my site קישור נסתר. The pages translated into English exist in the back office, and the menu has been synchronized.

Symptoms:
The new language, English, does not appear in the language selector, and the URLs are not functional on the front end.

Questions:
How do I display the new language in the selector?
How do I make the URLs functional on the front end?