If your pendrive or removable drive (after selecting it in This PC) has BitLocker button disabled (in Protect section of Drive Tools tab) or if you can’t see it listed in BitLocker itself then it is (currently) not supported. Most guides you’ll find will tell you that the destructive way of formatting drive is the only option.
That turned out to be not true, at least in my case. Simple deactivation of pendrive’s partition using DiskPart solved problem.
Of course you need Windows 10 Pro, because “lower” editions of this system does not have BitLocker.Read More “Can’t enable BitLocker for pendrive or USB removable drive”