Want to update ipad 6th gen to 16.3 but it says i cant install

Things tried: shutting down my ipad, deleting more space, connecting it to a computer, and deleting a lot of system files. I did press "Check for Update" but it tells me the current version and I need the download screen.

Is it not available on IPads that are my gen or is it some bug?

6.92 GB free storage

6th Gen

Capacity 32 GB