Hello Victor,
Thanks for writing to the Community. If you're locked out of your Surface Pro X due to BitLocker and can't access the recovery key. Try to check Your Microsoft Account: If you used a Microsoft account, your recovery key may be saved online. Go to Microsoft's Recovery Key https://account.microsoft.com/devices/recoverykey page on another device and log in to see if it's there.
Look for other copies online, check any printed copies, USB drives, or emails where you might have saved the key. If it’s a work device, ask your IT admin, as they may have it stored. If all else fails, the last resort, is doing a clean install of Windows on your device.
Hope this helps. If you needed more help or have more questions, please feel free to reply.
Cheers,
Res