STV is unknown at this stage if it will be continued past September. Your simplest method at this point to stay long-term is get married and apply for the non-O (married to a Thai) visa.
Mariana Lourenço. So it's not a VOA. It looks like you have visa waiver under the bi-lateral agreement with Brazil. I'm not aware if you are eligible for a covid extension. My advice would be to check with your immigration office. You may be eligible if the bi-lateral is treated the same way as an exemption