It's ok. Now i can login my facebook back! I've search a few solution on google. Then suggest me to login fb to the device that i've been login before. So i try to login using my mom phone because i've used it before. It's work ! I can login my fb on my mom phone. Then, i click on the menu. Then choose code generator. I copy the code and used it to login fb on my phone.
Tq very much for helping me instead.