You are very close. You are just missing definition of the source - "source_name".
map.addSourcePoint("source_name", QtPositioning.coordinate(51.9854, 9.2743)); map.addImagePath("image", Qt.resolvedUrl("./images/position-circle-blue.png")); map.addLayer("image_layer", {"type": "symbol", "source": "source_name"}); map.setLayoutProperty("image_layer", "icon-image", "image"); map.setLayoutProperty("image_layer", "icon-size", 1.0 / map.pixelRatio); map.setLayoutProperty("image_layer", "visibility", "visible");