Le portail francophone de la géomatique

symbol = QgsSymbol.defaultSymbol(self.layer.geometryType())
        svgStyle = {'name': path/to/symbol/TOWERS02.svg', 'size': '4'}
        symbol_layer = QgsCentroidFillSymbolLayer.create(svgStyle)
        
        if symbol_layer is not None:
            symbol.changeSymbolLayer(0, symbol_layer)

        renderer = QgsSingleSymbolRenderer(symbol)
        if renderer is not None:
            self.layer.setRenderer(renderer)

        iface.layerTreeView().refreshLayerSymbology( self.layer.id() )
        self.layer.triggerRepaint()