From the looks of your other post, you're currently here as a visitor: https://www.reddit.com/r/ukvisa/comments/lhi2k4/six_months_leave_to_remain/

You can't renew a visit visa unless you're receiving private medical treatment, so you need to leave the UK by the end of your 6 month visa waiver period. 6 months is the absolute most time you can remain in the UK as a visitor unless you were given "exceptional assurance" due to being unable to return to your home country.

Since you're from the US then there is no reason you can't return to the US (flights are still operating regularly), if you want to move to another visa type you will have to do so from your home country.