Changing email / Allowing passkey login / Other auth stuff

Would greatly appreciate if I could change my email in use (since I use a custom email and not the one provided by Google).
This came up when paying with Link, or trying to, since it forced me on my gmail instead of my custom email that has all my cards linked to.
Passkey login would also be awesome, I use 1Password and it lets me super easily and quickly login with passkeys.