If you apply in your home country for a non-immigrant visa, you will receive an OA visa. To get an OA visa you must show proof of health insurance that covers COVID. It would be a good idea to maintain the insurance you now have, assuming your insurance provides coverage in Thailand. From October 1, 2022, the minimum coverage is USD$100,000.00 (3,000,000 Baht).
If arrive on a tourist visa then convert that to a non-immigrant O visa in Thailand, there is no proof of insurance required, but you can buy adequate insurance for much less money.