Pip renewal advice

[Elasticatedwaist]

Ds2 is 22 and living at home, I applied for PIP for him 4 years ago. The claim is
Coming to an end and We’ve just received the renewal form.

Will he be asked to have a face to face assessment again ?
Do we need to ask the doctor for another more recent supporting letter or can we send the same one ?

He has Aspergers and epilepsy.
Thanks for any help. We are stressing!!

He may not need another assessment if nothing has changed and many areas still aren't doing them due to covid, they are just doing phone assessments.