Based on plenty of intra-EU Ryanair flights I never had the impression that they check for the indicated document but just a valid document matching the passenger. It’s not indicated on the boarding pass and don’t think they can see it on the computer. Probably I have already travelled with a document different from the one indicated online and nobody has even noticed. I would not worry too much about it.
That may well be different from what official sources tell you.
Credit:stackoverflow.com‘