Hello,
Bitlocker is a 48-digit number -only code.
Have you looked into the Microsoft account here to see if it is stored there? https://account.microsoft.com/devices/recoverykey
Any chance your laptop was purchased used, or already set up for you? Or was it gifted? Or have you set it up with a different account at first? The key is stored with the very Microsoft account used to set up the computer for the first time, even if you had got rid of that account and set it up with a different account. So, if your computer was set up by anyone at the store you bought it from, it would be that person's account.
If you set it up with school or work account, it is worth checking here as well https://aka.ms/aadrecoverykey sign in with your work/school email credential in that case.