To add the outline map layer:

In QGIS, go to the Layer menu option, select Data Source Manager, and, in the left panel, choose WMS/WMTS.

Make sure the Layers tab is selected, and click the New button. This will open a new dialogue box.

Give the map a name ("Tim's Custom Mapbox Outline" or something similar -- adding my name is so you know who to bug if it stops working).

Set the URL to: https://api.mapbox.com/styles/v1/ragtagtag/ciry26ojy003tgynmznkc1a6q/wmts?access_token=pk.eyJ1IjoicmFndGFndGFnIiwiYSI6ImNqdHpzOGh2ZjFtNWQ0ZnBsYmNlZXpoNGQifQ.TQX0oaw1nv2g6lHeCmSVwg

Click on OK to close the dialogue box. Then, next to the "New" button, click on "Connect". (If anything goes wrong, send me the error message that will appear here.) If everything goes right, it'll switch to the Tileset tab, with a highlighted layer. At the bottom, it will allow you to change the map name, if you like. Below this, click on "Add".

You should now have a new layer with the right outlines.
