@Bill ******
@Michael ********
@Viki *********
I didn't have any embassy letter, only fill up application form for extension, and signed another 3 forms given by the immigration (for covid extension, and awareness of not to overstay papers), just have to attach 1 photo, and provide signed copies every page of the passport, then paid 1900 at counter 7 in Chiang Mai Immigration Office (airport), waited a few minutes then got the stamp up to Feb 28, 2021, not "under consideration" stamp. FYI. Good luck to you all.