uhm.. when i have only one choice of legal move? i thought that after i had posted this topic
What is the forced move?

Yes , that's the forced move.
Just one small note.There are moves that are forced because they are the only legal moves and moves that are "practically forced" because they are the only ones that don't lose the game.
You will see the term "practically forced" in books or when watching GMs commenting on a game.
thank you for your detail explanation.
what is the "Forced" in the computer in the engine analysis?