WMTS Service works in ArcGIS Pro but not ArcGIS Javascript - uses direct XML file, not service

[mjperez-usgs]

I am trying to consume this site's WMTS service as described: https://rangelands.app/support/19-viewing-rap-data-in-your-gis

I can load it into ArcGIS Pro using their directions and URL, but I cannot get it to load in ArcGIS Javascript SDK, as it always seem to try to make a GetCapabilities request, which doesn't seem to exist on their server. In Pro I can see it's using the exact URL I gave it (the .xml file).

Is there a way to not have the 4.0 SDK (I'm on 4.34) not make this GetCapabilities request? I am not sure what Pro is doing differently.

For reference I am doing this: 

let wmts = "https://rangelands.app/wmts/vegetationWMTS.xml";

            const wmtsLayer = new WMTSLayer({

                url: wmts,

                title: "Rangeland Analysis Platform",

                id: "rangeland-analysis-platform",

                visible: true

            });

            map.add(wmtsLayer);

And I have ensured this URL is allowed per my server's connect-src policy.

[YannCabon · Accepted solution]

Hi,

The server you are trying doesn't have CORS headers configured for JavaScript (and the Maps SDK) to correctly fetch the capabilities file.

[mjperez-usgs]

Thanks. I will contact the developers and see if I can get them to set it up.