Are you looking something like that?

const { map, picker, utils, broadcast, store } = windyAPI;

const customIcon = L.icon({ iconUrl: 'wPin.png', iconSize: [18, 18], }); const markerOptions = {title: "myPoint", icon: customIcon}; const marker = new L.Marker(**[lat**,**lon**],markerOptions).addTo(map);