1. Use explorer which support Ordinals or other NFT such as
https://ordiscan.com/2. Enter your Bitcoin address on search bar.
3. Click on tab or section which shows any rare sats.
The website also have statistic and price for such satoshi on
https://ordiscan.com/rare-sats, but i don't guarantee it's accuracy.
Or can use this website
https://magiceden.io/ordinals/discover-raresatsI see this is very bad for privacy by typing a Bitcoin public address and check Rare Satoshis, perhaps only for fun and nothing more. If want to do this, to satisfy curiosity, people can check it with Tor if they want.