You Can extend 60 day visa for 30 days only once! After that there's only two options: 7 days visa to live the Kingdom or 60 day Covid extension (but be aware, that You need to pick it up after 15 days in the same immigration office - important if You plan to travel)
And do You know, by the chance, if I can get Covid visa in Bangkok in the same day? In Chang may office they told me it will take 15 days but in Bangkok it is possible