We have a WMTS that is sourced from Geoserver that when loaded into ArcGIS Onlione we get the following response in the browser development console.
index.html:1 Access to fetch at 'https://geos.oceanwise.eu/geoserver/gwc/service/wmts/1.0.0/WMTSCapabilities.xml' from origin 'https://oceanwise.maps.arcgis.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
The WMTS is https://geos.oceanwise.eu/geoserver/gwc/service/wmts?
This service is used in other applications without issue including the Classic version of AGOL. What is it that AGOL is expecting from service that is not provided and causing this issue?
