Thanks for the replies.
According to their website it says, “closed on Saturdays, Sundays and Bank Holidays”
Looking at the NHS info it says Urgent Care is in the Pallion health Centre and shows photos of it as well as directions to it. I also found something from the Sunderland Echo local newspaper from 2021 they said Urgent Care was being moved into the main hospital building, which is where it was when we visited. If the NHS had given the correct details I wouldn’t have used that entrance/car park in the first place!.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!