we are talking about the TDAC. you can do it within 3 days of arrival. you can even do it inside the airport in thailand. filling it out barely takes 5 mins. you get the approval mail within seconds. no you dont need a printout. the officer usually does not even want to see it as its in the system and linked with your biodata anyway… no you dont get denied if you not have it. airport has a separate queue for people without it. they additionally have TDAC terminals.
how hard can it be to fill out the TDAC before you go? 🤣