Bitlocker key requested on the boot, but I don’t have any key

Hi Yann, 

First of all, is this device is set up under your Microsoft account, or does the business own it? 

If it is business, then their IT will be able to provide you a BitLocker key from Entra Admin. 

Or you can simply get the keys from  https://account.microsoft.com/devices/recoverykey

More things to check are temporarily disabling any active VPN connection, then opening an incognito or private browsing window in your web browser, and going to the above-mentioned link and getting the key from there.

If you are still having issues, connect your device to another Wi-Fi network, such as a mobile hotspot network, and then see if you can view the BitLocker recovery key.

Please let me know if this helps.