I'm not sure exactly what that might look like, but if you look at crypto wallets for example, you could have a browser extension (or something like Apple Pay)

I'm not sure exactly what that might look like, but if you look at crypto wallets for example, you could have a browser extension (or something like Apple Pay) that's able to custody the private key and sign transactions. Once you have it set up, it would be much easier than entering a CC number.