My F1 visa is expiring on December 2021.?
If you are presently in US, there is no urgency for you to renew your F1 visa. You only need the visa to be current and valid if you need to enter US. So as and when it is possible to visit your home country comfortably, you can renew it and come back to US with a renewed visa. It can be even past your visa validity date. Only make sure dont leave US .