@John **********
Not sure John. I have in the past couple of days completed all the required Visa and COE at the Embassy in Doha and had to show my various documents including, a marriage certificate and proof of where I would be staying from my wife on completion of the quarantine period. The information I attached was from the Embassy Website and this is the direction I followed in order to secure my travel documents. It is always worth checking out any updates to the entry process, as pointed out above, as entry requirements change frequently. Take care and hope you get your dental work carried out in Thailand.