You need your national insurance number.
If you don't have a national insurance number you need utility bills etc. Why don't they accept a university campus card or student union card as photo ID? Not everyone has utility bills.
https://www.gov.uk/apply-for-photo-id-voter-authority-certificate
🐦🔗: https://n.respublicae.eu/catherinerowett/status/1617440366378250241