@Jo ******
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.