Преврати
map.addControl(
new MapboxDirections({
accessToken: mapboxgl.accessToken
}),
'top-left'
);
в
var directions = new MapboxDirections({
accessToken: mapboxgl.accessToken
});
map.addControl(directions,'top-left');
map.on('load', function() {
directions.setOrigin([12, 23]); // can be address in form setOrigin("12, Elm Street, NY")
directions.setDestinaion([11, 22]); // can be address
})