Hello Nils,
Thank you for posting question on Microsoft Windows Forum.
Well! BitLocker is a Microsoft Windows feature, and the recovery keys are typically associated with a Microsoft Account, not a Gmail (Google) account, unless that Gmail address is the one you used to set up or log into your Microsoft Account.
If your Windows device was set up with a Microsoft Account. Try to follow below steps:
- Open a web browser on another device.
- Go to the official Microsoft BitLocker Recovery Key page: https://account.microsoft.com/devices/recoverykey
- Sign in using the email address and password for your Microsoft Account (which may be your @gmail.com address).
If you are successful, you should see a list of your BitLocker recovery keys associated with your devices. Match the Key ID shown on your locked Windows screen with the Key ID on the website to find the correct 48-digit key.
Hope the above information is helpful!