If you plan on getting health insurance in Thailand anyway, you can apply for the one year OA retirement visa in your home country online. You have to show 800,000 baht in your home country bank account and a few other things, including the paid health insurance policy, but you enter Thailand with a one year visa.
If you don’t have a high profile job or own a lot of property here, and just a regular Thai person, you’ll probably get denied. I went through that with my then-girlfriend back in 2017. Had to bring her to US on a K1 fiancé visa as her tourist visa was denied. Too many Thais not coming back after the visa ends. That’s why. Been happily married 7 years now and living in Thailand.