OGC Map Tile Loader Extension

We’re loading map tiles into Create, and we’d like to pull DEMs from the Open Topography API, which is OGC 2.0 compliant. In the Map Imagery Selection Custom Server pulldown, there are slots for Base URL, collectionID and authentication.

One can apparently access the DEMs by calls to the API which look like this:

https://portal.opentopography.org/API/globaldem?demtype=SRTMGL1&west={W}&east={E}&south={S}&north={N}&outputFormat=GTiff&API_Key=xxxxxxxxxx

How should we parse this URL so that the various components fit into the Base URL, collectionID and authentication slots? And has the extension been tested with the Open Topography API?