Starting Oct 1, only those who have been fully vaccinated against Covid-19 or have a negative antigen test result will be allowed to dine-in at restaurants and seek out services deemed a high risk for virus transmission in "dark red" provinces, where maximum Covid-19 restrictions apply.

https://www.bangkokpost.com/thailand/general/2176823/jab-proof-for-dine-in-on-oct-1