@Anushka Weerasinghe, Thanks for posting in Q&A. For the other two drives, please firstly check if the two drives are encrypted. If yes, you can run the command in the following link to manually backup the BitLocker recovery key to Azure AD (Microsoft Entra):
For the script to do this, here is a link for your reference:
Note: Non-Microsoft link, just for the reference.
Hope the above information can help.
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