One of these links may be useful:
https://support.microsoft.com/en-us/windows/finding-your-bitlocker-recovery-key-in-windows-6b71ad27-0b89-ea08-f143-056f5ab347d6
https://support.microsoft.com/en-us/windows/find-my-bitlocker-recovery-key-fd2b3501-a4b9-61e9-f5e6-2a545ad77b3e
https://www.tenforums.com/tutorials/130909-find-bitlocker-recovery-key-windows-10-a.html
https://www.tenforums.com/tutorials/97390-use-bitlocker-repair-tool-recover-encrypted-drive-windows.html
https://www.tenforums.com/tutorials/37060-turn-off-bitlocker-operating-system-drive-windows-10-a.html
https://www.tenforums.com/tutorials/97242-unlock-os-drive-encrypted-bitlocker-windows-10-a.html
https://www.tenforums.com/tutorials/39732-backup-bitlocker-recovery-key-windows-10-a.html
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