For example, my local server is at an IP ADDRESS 192.168.1.40 and for various reasons I moved it to 192.168.1.55
Can I just change the server name for a storage somehow?
To change the storage url, you can manually edit ~/.duplicacy-web/duplicacy.json (while the Web GUI is not running), or simply delete the storage and recreate a new one with the same storage name and the new url.