That's the marriage visa. You need to deposit 400,000 THB in the bank for 3 months a year for that. 800,000 THB if you are 50 or older for a retirement visa.
I lived both in Indo and Thailand. Different situations here. Indo needs to be more open to the world whereas Thailand has been open for a long time. However, I don't think it's cheap to get a legal status in Thailand. Both countries are very protective.
This is tricky. In my case, I uploaded my resident registration in English from Korea. You may be able to upload some official thing with your name and address. They will email you if some documents are not good enough. Then you can attach documents to the email reply. That's what I did.
I got screwed up when I missed the flight because they didn't give me a break. Now, they are making a little more sense. You still may get hacked. I got 4 different emails from hackers after I registered.
And you'll also be greeted by a hacker who probably has the copy of your passport. The system has been hacked repeatedly. I received four different hacking emails.
I had entered three times during Covid. They rejected me for bogus reasons even when I got in with the same documents before. This means it's all up to the person who is processing your case even if there was a rule. So, you need to get it if you don't wanna miss the flight or get fined unexpectedly. I never felt any friendly atmosphere with Thai Pass.
