Hi there, and welcome to the GrapheneOS discussion forum! Thanks for your question.
I had a quick search and I noticed that an existing thread on this topic already exists: https://discuss.grapheneos.org/d/5379-hotspot-and-wifi-on-pixel-7a-lynx.
If you have any follow up questions, you can ask in the other thread. I am locking this thread to help keep the discussion in one place.