@Laurent *******
You can apply for a COVID extension...but there is no guarantee that it will be approved.
Apply before your current permission to stay date expires
But not later than January 25th
Go before that date as the extension - if granted - is from your current COVID extension ending date.
The COVID extension is not guaranteed. In fact we have reports of this happening in recent weeks:
...of extension being denied
...given 7 days to depart Thailand
...granting less than 60 days
...requesting to see a confirmed booked flight out of Thailand.
And/Or
...a letter from your home country Embassy requesting the extension
Be sure that you have a TM30 address registration filed where you are living.
And be prepared to answer the question... Why are you still in Thailand?
The COVID extension is not guaranteed...and as you stated this is not your first COVID extension request.
If you have been in Thailand for using many extensions...Including multiple COVID extensions....
Then the newly published Thai Immigration Order should be of interest to you.
The Immigration Officers have been instructed to be stricter in granting the COVID extensions.
And recent reports of less than 60 days are reported granted...even the 7 days to leave Thailand stamp.
Read the bottom 5 lines of right hand column...
Suggest you have a Plan B in mind.
Good Luck