Do I need to show a rental contract for a 60-day family visit extension at Chaengwattana if I’m in an Airbnb?

The 60-day family visit extension at Chaengwattana does require proof of residence, which can include a TM30 receipt for foreigners residing in a location and possibly documentation of your Airbnb stay, like reservations. The type of entry visa you used is important; those on a Non-O entry apply at Chaengwattana, while those on a 30-day visa exemption or a 60-day tourist visa go to the Muang Thong Thani immigration office instead.