Facetime and Message Issue

Since I just bought the new iPhone 8, I gave my mother to use those iPhone 5 for some needs of her. I tried to delete iPhone then create new account for her and it works. I got finished all of the instruction and I managed to get to the home screen. But I can't activate my mother Facetime and imessage with her new account. She wanted to use this iPhone because she really needed to use the facetime . Can someone help me through this out?