Thiên Đăng hi, no they didn't require it... I would have thought the evisa form is the same for all DTV frelancer applicants and there was no "slot" to provide that on the website
nobody needs to show that for the freelancer subcategory 🙂 The only location-related proof they need is to show you're applying from outside of Thailand. And for that I used the scan of my passport page showing my entry stamp to Vietnam + a hotel booking reservation pdf