AFAIK the recommended way is to open a bank account through smaller banks (aka neobanks). They just send you a card to address specified and once you activated it you (first) get a bank account for payments and (second) can use it to prove address for others. Also, if you legally rent then you get the council tax documents, though it takes roughly a month for them to send. This is another proof of address. And the bills of course, but again it takes a month or so to receive the first letter.

So it's unclear how a digital ID solves anything in regarding the proof of address.