Hi Kacper Paczkowski,
When you enable BitLocker encryption, a BitLocker Key is generated, which is used to unlock the encrypted hard drive. If you forgot your BitLocker Key, you could use the BitLocker Recovery Key to unlock your hard drive. The BitLocker Recovery Key is a 48-bit number or letter combination that can be generated or backed up when BitLocker encryption is enabled.
For the details about how to find your BitLocker Recovery key, please see Finding your BitLocker recovery key in Windows - Microsoft Support.
If you are still unable to find the recovery key, you may need to contact Microsoft Support team (Contact Us - Microsoft Support) for further assistant.
Important: Microsoft support is unable to provide, or recreate, a lost BitLocker recovery key.
Hope it helps.
Kind regards,
Lei