Not true. It is working for everyone else. The problem is at your end. You probably just need to sign in to Lichess on the app.
Chessnut issue

You should contact Chessnut e-mail support at contact@chessnutech.com. They will explain to you the exact steps you need to perform in order to get lichess working for you again.
It is now over one month that I cannot connect to lichess platform via my chessnut app. It seems chessnut has removed lichess from its app completely.