interactions - draw

add a vector layer

        
           const vector = new ol.layer.Vector({
               source: source
           });
           this.map = new ol.Map({
               target: 'olmap',
               layers: [this.osm, vector],
               view: this.view
           });
        
    

create an interaction

        
           this.draw = new ol.interaction.Draw({
                 source: source,
                 type: 'Point'
           });