Have particularly sensitive data on an external disk? If the disk is formatted as Apple File System (APFS), you can encrypt it in-place on macOS by focusing on it on the Desktop or Finder sidebar and choosing "Encrypt [disk name]" from the context menu (accessed by pressing VO-Shift-M). #TipTuesday https://www.applevis.com/podcasts/how-encrypt-external-disk-macos
How to Encrypt an External Disk on macOS | AppleVis

In this episode, Tyler demonstrates how to encrypt an external disk on macOS for improved security of the disk's contents.