Some more information here
https://www.tatnews.org/2022/04/thai...om-1-may-2022/
Especially those cannot meet vaccinated requirements:
International travellers who are unvaccinated or are not fully vaccinated will also no longer be required to show proof of a pre-arrival negative RT-PCR test nor undergo an arrival test.
They are required to register for a Thailand Pass with a 5-day hotel booking and an insurance policy with coverage no less than US$10,000 (reduced from US$20,000).
Once arriving in Thailand, they must proceed to undergo the quarantine for 5 days and undergo an RT-PCR test on Day 5.
Exception is made for unvaccinated travellers who are able to upload proof of a negative RT-PCR test within 72 hours of travel via the Thailand Pass system, they – like those fully vaccinated – will be allowed entry and are free to go anywhere in the kingdom.