Importing OpenPGP public keys using the Passwords and Keys utility is broken since Tails 4.0 (October 2019). (#17183)

Do so from the Files browser instead:

  1. Choose Applications ▸ Files to open the Files browser.

  2. Double-click on the OpenPGP public key that you downloaded. The key must be in the armored format, usually with a .asc extension.

  3. Choose Open With Import Key.

  4. The imported OpenPGP public key does not appear in the Passwords and Keys utility. But, the key should appear in the list of keys available for encryption when encrypting text with a public key using OpenPGP Applet.