Onion-Location is a non-standard HTTP header that websites can use to advertise their onion counterpart.
If the website that you are visiting has an onion site available, a purple suggestion pill will prompt at the URL bar in Tor Browser displaying ".onion available".
Wenn du auf ".onion available" klickst, wird die Website neu geladen und zu ihrem onion-Pendant umgeleitet.
Translation notes: Do not translate.