Successfully applied for 60 day covid extension today at Chaeng Wattana - I've had multiple in the last 6 months
If you book a time slot you have to explicitly go to the immigration official and inform them - my time wasn't called and this was what I was told.
If you've been here over 90 days they will ask you to do 90-day report - make sure keep in passport and you have to also photocopy this along with EVERY page since the visa you entered on: not just last stamp and visa etc
TLDR : Answer Summary
A user successfully applied for a 60-day COVID extension at Chaeng Wattana, sharing important tips about the process. They mentioned that booking a time slot requires informing the immigration official upon arrival, highlighting that appointments aren't automatically acknowledged. Additionally, for those staying in Thailand for over 90 days, a 90-day report is required, emphasizing the need to photocopy every page of the passport from entry, not just the visa stamp.