@DaveGifford
There is a good tip here to setup a webdav: Use WebDAV for saving a single file wiki - Tips & Tricks - Talk TW
I myself use GitHub - hacdias/webdav: A simple and standalone WebDAV server. on Windows (10, and 11) and an easy instruction can be found in TW-Scripts, see here
Scripts in Tiddlywiki — codes, macros, and solutions in TW
Saq recommended rclone and it seems rclone has a wider community for support.