Sync webdav don't work at all

I’m using last version of DTPO 2.11, and an asustor NAS with last version of ADM. I created my secured webdav server (https).
on sync panel, il enter the address and name and password.
then sync doesn’t work, even if DTPO created the location on the webdav server (sync file). on the log panel I see “forbidden (403)”

do you have any idea why syncing doesn’t begin?

thank you

We don’t do support for specific WebDAV instances but what did you put in the URL field?

I use the local address of the NAS https://192.XX.XX.XX:9802/YYY/ZZZ
even with not secured webdav it doesn’t work.

I actually use dropbox but I’m looking for local sync (same database for two computers). Is there another solution?

Can you access WebDAV using that URL when using Go > Connect to Server in the Finder?

see picture with error