Is ARC accepted on UK domestic flights to Belfast

Does anyone have recent knowledge of whether an ARC accepted on UK domestic flights to Belfast?? - I am due to travel next month.

The ARC says "NOT A TRAVEL DOCUMENT" on the back.

I am due to travel next month but cannot get categorical advice anywhere - neither from EasyJet/ our solicitor or from Migrant Help.

We will so grateful if anyone can advise on this, thank you.

Can you clarify what an ARC is? We are not familiar with all immigration acronyms and that one is new to us.

Assuming that it is a purely domestic flight within the UK, there are generally no checks carried out at the airport that you land in.

Do you have any other form of photographic identification?

Probably is this: https://www.gov.uk/claim-asylum/after-your-screening
"asylum registration card"