As Microsoft ends support for Windows 10 Mobile,
the normal text message backup method has stopped working.
Phones running Windows 10 Mobile do not back up messages after mid-September 2019.
As a result, the only way to backup new messages from a Windows 10 Mobile phone is directly from the phone.
With version 2.3.66, this is simpler than ever.
Simply download the WP Message Backup app directly on your phone.
In the setup process, click "Add this phone", or you can also add it later from the app bar (...) menu by clicking "Import From System".
Leave WP Message Backup open and wait until the import is complete. Importing may take several hours.
As always, tap the hamburger menu button (≡) to see your imported messages.