Who gets free healthcare in UK?

Hospital treatment is free of charge for people who are ordinarily resident in the UK. This does not depend on nationality, payment of UK taxes, National Insurance contributions, being registered with a GP, having an NHS number, or owning property in the UK.

https://www.gov.uk/guidance/nhs-entitlements-migrant-health-guide#:~:text=Hospital%20treatment%20is%20free%20of,owning%20property%20in%20the%20UK.