I went to Thailand with a tourist visa and just got a rental agreement. Stayed for 90 days then left. Or just get a reservation agreement and pay xxx amount to the Agent to reserve the condo and agree to pay the full amount at xxx date Also a scanned copy of my passport and the condo owner’s Thai ID, as well as a digital copy of the rental agreement.
This works if you were already in Thailand and can just apply at a nearest foreign embassy.