@Johnny ****
it cannot be done online, the first time after coming back into Thailand. It has to be done at the relevant Immigration office.
For DTV holders, it can only be done online if the 180 day stamp is extended. Meaning the first 90 days after the extension could be done online.
But hardly any DTV holders are trying to extend their 180 stamps at immigration because it’s just too much hassle, and as much if not more work than the original application required.