Unable to access BitLocker-encrypted USB file on Mac

If someone sent you that encrypted drive, then ask them to send you the drive again using another encryption method that is compatible with both Windows and macOS. There are several different options available, but most will likely require installing some third party software on both macOS and the sender's Windows PC. VeraCrypt (formerly TrueCrypt, but was forked when the original developer abandoned the project) is one option.

Here is a paid third party app that says it can read Bitlocker encrypted drives. I have never used this software and know nothing about it so make sure to do your own due diligence to ensure the app is safe.

https://www.m3datarecovery.com/mac-bitlocker/

You can try installing Windows 11 into a Virtual Machine in order to unlock & decrypt the Bitlocker drive.

https://www.parallels.com

Go back to Windows machine to unlock it with correct password or recovery code, copy the files to an exFAT formatted USB drive, then come back to your Mac to open the file(s).

Hope this is helpful.