Setting up WebDAV think - box grayed out

I’m attempting to set up WebDAV Sync using Devonthink Personal. I think I’ve correctly set up the WebDAV server on my host, but when I enter the information for the host in the dialog, the entry for WebDAV remains grayed out. Evidently, something is off, but I can’t tell what. I put an incorrect password in to test, and I don’t get any sort of dialogue box alerting me to an issue, so it seems that I’m in the dark as to why things aren’t clicking. I realize that this question is somewhat vague, but I am not exactly sure where to proceed from here and I would be very happy for some guidance!

Is anything logged to Windows > Log?

No, nothing has been logged. Happy to provide any further information.

In DEVONthink, hold the Option key and select Help > Report Bug. Also include a screencapture of the WebDAV settings you are trying to use for the sync location.

Sent. I am guessing the issue is on the side of my server, but it would be helpful to know what exactly is happening. Thanks.