Then you can do whatever you feel like. There is no clear official policy which is consistently followed.
In theory the test result should be recorded in the morchana app, but this app seems to be a complete mess which hardly anyone can be bothered.
My hotel gave me clear instructions about the self test to mail it to them (they never even mentioned morchana app). So that's what I did. This seems to be the usual way.
If they don't give any instructions at all, seems the hotel is just assuming you'd use the useless morchana app which doesn't work. Don't worry about it.
If your hotel gave you clear instructions, just do it now and send them the result to make them happy. A day or 2 dlate doesn't matter. Could always pretend you did the test on time but forgot to mail it to them if that gives you peace of mind. (But don't worry about it really)
If your hotel didn't give you any instructions or was vague and confusing about what you had to do, then don't bother with it and use it later on for yourself.
About the not being able to update on the date when apply, I "solved" that by depositing a token amount, or withdrawing that token amount the other year.
Chaeng wattana. Last time was March last year. Copy of history fixed deposit bankbook + guarantee letter of bank of the exact amount on that day. Then I didn't need the history from the bank itself.
so this is a new rule about the way you have to prove the banked money ?
New = I mean starting April 2020 or later ?
Because up to April last year (was my last extension), I made copies of my updated fixed deposit bankbook and a letter from the bank guaranteeing the amount (not the history of transactions) on that date (of applying for extension).
So have the rules changed since then, or maybe I am misunderstanding something ?