When you log into Coinbase for the first time from Bitkey, you’ll be prompted to authenticate by clicking a link sent to your email. If you encounter issues with authentication, it may be due to the iPhone Private Relay. Disabling your Private Relay and trying again should resolve the problem. Private Relay can sometimes make it appear as if you’re logging in from a different device, which can prevent authentication. You can re-enable Private Relay once the authentication process is complete. Additionally, using a VPN may also cause similar authentication issues.