Non-reproducible with current version of JSON file
対処法
1. Download the JSON and add an 's' in the URL section as shown below; "url": "<a href="https://basemaps.arcgis.com/arcgis/rest/services/World_Basemap/VectorTileServer" target="_blank">https://basemaps.arcgis.com/arcgis/rest/services/World_Basemap/VectorTileServer</a>", 2. Save the JSON file and update the style layer.The web map is displayed the basemap.