@Yui ************
Thanks. I got one of those and included it with the initial application. It still took 9 days to receive this message: "Thailand Pass system has rejected your registration due to Your hotel does not confirm your booking on Thailand Pass within 72 hours. Please reconfirm your booking and reapply for Thailand Pass.
If you would like to make adjustments or attach additional documents, please update your submission by clicking the 'check status or edit' tab via the following link:"
Which I did and received the same message as above within a few hours. Anyway, I'll be trying some of the other advice presented here.