Hover your knee off the ground when you are in the all-fours helps. Like don’t put your whole weight on it. Do poses that don’t put as much weight on your knees. Look for better ground to practice, grassy areas.
When I yoga outside, it’s the last suggestion I use the most. My knees are also sensitive, and finding a flat surface, then using my usual sorta thick yoga mat works well.
I lost one, sent the emails I might need to another account. So that was ok but I forgot to change the email on every freaking service I use so it was very difficult to recover some accounts.