Depends on which client you’re using to run 🏃 this 🟣 (nostr).
Do you know which one?
Damus, Snort and Iris are some that come to mind if you’re not sure.
Discussion
Damus.
Upload your photos to https://nostr.build
Then take that link and go to your profile and click edit and paste in the banner image field.
Let me know if you have any more questions!
🤙
You da man!!