i directly contacted the hotels that i’m interested in, and asked if they are an AQ or SHA hotel, if they have any one day package based on the new rules. The hotels got back to me with the prices of their packages. But the link provided by Kevin above maybe more useful.
Do you mean getting endorsed in Singapore or Thailand? Is it for Thai work permit? If yes you can go to any private hospital in Thailand and tell them you need a medical certificate for work permit purposes.