This might be helpful for someone.
This is what we did to get covid extension in Phuket.
You have to go to the main immigration centre in the Phuket town upstairs. Dress respectively. We were in the office for 45 minutes. If you have everything in order, it's very easy.
You will need a screenshot of the TM30 website from your hotel (when you check into your hotel they will register you on the TM30 website, just ask them for a screenshot of you on the system for immigration),
a TM7 form and an STM2 form (both these forms available at the immigration office or you can get them online. Also, an affidavit form that you get in immigration.
you will need your passport,
a signed copy of your passport page,
Signed copy of the TM6 card
a signed copy of the 30 day extension in your passport you already have along with your actual passport.
You will also need 2 X passport photographs of yourself.
You pay 1900baht and then leave your passport overnight and collect the next day.
TLDR : Answer Summary
The post outlines the steps to obtain a Covid extension in Phuket, Thailand, emphasizing the necessary documents such as the TM30 screenshot from the hotel, TM7 and STM2 forms, and passport-related items. It mentions the immigration center location, dress code, and fees associated with the extension process. Comments provide insights on personal experiences, document requirements, and advice on filling out the affidavit form.