Step by step, add a WMTS service of aerial imagery or map layers in QGIS and ArcGIS, with points of attention for coordinate system, token and performance.
In QGIS open the Data Source Manager and choose the WMS/WMTS tab (shortcut Ctrl+Shift+W). Choose New, name the connection and paste the service URL, the address of the capabilities document. Choose Connect, select the layer and pick the tile matrix set for your coordinate system, for example EPSG:3857 for Web Mercator or the code of your national grid. Choose Add. Then set the project coordinate system to the same EPSG code so the tiles line up with your other layers without reprojection. If your service uses a token, copy the full URL or set up authentication through the QGIS authentication configuration. The documentation for your tenant says which variant applies.
In ArcGIS Pro, on the Insert tab choose Connections, then Server, then New WMTS Server. Enter the service URL and add the connection. You then find the layer in the Catalog pane under Servers and drag it onto the map. Here too, check that the map coordinate system matches the chosen tile matrix set.
A blank map usually means the chosen tile matrix set does not match the project coordinate system, or that you zoom outside the available levels. A 401 or 403 error points to a missing or expired token, or to access that was issued for a fixed period and has ended. If you see an old image after new data was delivered, refresh the layer and clear the QGIS cache if needed. If a layer is slow, check that you work at a suitable zoom level: WMTS serves pre-made tiles, so speed does not depend on how complex the image is.
