Jay Storey. I don't think you can, as you now have a "live" visa, and you cannot apply for another whilst you already have one. I mean you can try but I don't know if you'll have success. You might need to contact your embassy and see if it can be changed. The criteria for STV is different than that of TR so it might not be easy
Subtle difference but you don't have a Visa On Arrival, you are visa-exempt (so you don't actually have a visa). If you want to convert to "retirement" visa you'd better act quickly as you're running out of time. Go to your immigration office and request the list of requirements to obtain the non-O visa based in being over 50.
Tobie Oud. Land borders and covid extensions are not related. The covid extensions are for people who could not return to their home countries due to covid restrictions.