There doesn't seem to be any other way though if you need webdav.
Looks like you need to set up that webdav server app and then, once it's running, if you type webdav you should see - according to that doc - something like this
WEBDAV SERVED LOCATIONS:
/path/mega/folder: http://127.0.0.1:4443/XXXXXXX/myfolder
/path/to/myfile.mp4: http://127.0.0.1:4443/YYYYYYY/myfile.mp4
The 2nd column, starting from http:// is your webdav URL to use with Joplin.
If they have an app that syncs a configured folder in background, you can use this + file system sync in Joplin. May be easier to set up.
