You might be able to recover your recovery key. This is what you can try: Boot from a Windows 10 installation media Enter recovery mode and open a command line I‘m assuming c: is your locked drive, enter: manage-bde -unlock c: -password You should be prompted for your password, enter it Now your c: drive should be temporarily unlocked. To retrieve your recovery key, type: manage-bde -protectors c: -get If this shows your recovery key, make sure to write it down correctly. After reboot you should now be able to enter the key and continue. In the future: Don‘t lose your recovery key again! BTW: This won't work if you never set a password in the first place. AFAIK you cannot set a password if you installed Windows in UEFI mode with TPM activated. If this is the case for you, you might be out of luck unfortunately.
Don't know, sorry. Are you sure you actually set a password in BitLocker? Or did you just use UEFI with PIN or maybe only UEFI with TPM module active? As far as I read you really need the recovery key if you want to unlock the drive and TPM was used. The steps with password only work if you use BitLocker without TPM because you need a password in that case to setup BitLocker.