You can go to your nearest immigration office pay ฿1,900 thb to get a 30 day extension…if you have already had your 30 day extension go to the nearest immigration office and apply for the 60 day COVID extension this extension is on the books until 25 Jan 22 and it may be extended again…good luck all extensions need to be completed at the immigration office if you get a visa you have to leave country and apply at a Thai consulate/embassy
1,900 thb then after that if the COVID visa is still ongoing after 25 Jan 22 go back to immigration and get the COVID extension which is good for 60 days… if you’re lucky enough to end your 30 days on the extension prior to 25 Jan 22 go back to immigration and get the 60 day COVID extension…this extension is basically unlimited some people have used it for the past 22 months non-stop since the pandemic began… good luck