Just to add, if you applied for the non-o in your home country you would be stamped in for 90 days on arrival. Your next step will depend on the type of non-o so as
@Ellie ******
says go talk to your local immigration office to find out their requirements. I'd do that ASAP as the retirement extension requires money in a Thai bank for 2 calendar months before you apply (unless you come from a country whose embassy issues income affidavits)