I consider that you have two choices.
Turn off BitLocker encryption on the external hard drive so that you can open and read it normally on your MacBook.
Or maybe some third party tool will meet this need on the Mac.
Some information in the link below may helpful to you.
Please Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
Hope this helps and please help to accept as Answer if the response is useful.