That position seems to have changed, I think? They are supposedly allowing people to buy Privacy Pass tokens without a Kagi account in-the-future™:
"Yes, this makes sense. This is possible because technically the extension does not care if you have an account or not. It just needs to be ‘loaded’ with valid tokens. And you can imagine a mechanism where you could also anonymously purchase them, eg. with monero, without ever creating an account at Kagi. Let us know here if you are excited about this, as it will help prioritize it."
https://blog.kagi.com/kagi-privacy-pass
They also provide a Tor hidden service which can be used with Privacy Pass (although you'd have to install their extension on Tor Browser for it to work)
"Yes, this makes sense. This is possible because technically the extension does not care if you have an account or not. It just needs to be ‘loaded’ with valid tokens. And you can imagine a mechanism where you could also anonymously purchase them, eg. with monero, without ever creating an account at Kagi. Let us know here if you are excited about this, as it will help prioritize it." https://blog.kagi.com/kagi-privacy-pass
They also provide a Tor hidden service which can be used with Privacy Pass (although you'd have to install their extension on Tor Browser for it to work)