If you look at an earlier version which uses full build syntax you can see it is new ol.geom.Point
https://openlayers.org/en/v4.6.5/examples/icon.html
If you have geojson data OpenLayers can load and parse it directly from the url
var vectorLayer = new ol.layer.Vector({
source: new ol.source.Vector({
url: 'your json url',
format: new ol.format.GeoJSON()
}),
style: ....
});
or if you have loaded the json yourself you can parse it into a features array, the geometry and any properties specified in a valid geojson will be included
var features = new ol.format.GeoJSON().readFeatures(your_json_data, {dataProjection: 'EPSG:4326', featureProjection: map.getView().getProjection());
Note that if your map view is not LonLat (e.g. it is web mercator) and you use readFeatures you must transform the coordinates to display the features in their correct location.
If your json is simply an array you must loop through to create each feature and add it to the source. You may also need to transform the geometry projection to view it.
var iconFeature = new ol.Feature({
geometry: new ol.geom.Point([lon, lat]).transform('EPSG:4326', viewProjection),
name: name
});
vectorLayer.addFeature(iconFeature);
If you have an array
in the form [[lon, lat]. [lon, lat], [lon, lat], .... , [lon, lat]]
you could create a single MultiPoint feature
var feature = new ol.Feature({
geometry: new ol.geom.MultiPoint(array).transform('EPSG:4326', viewProjection)
});
vectorLayer.addFeature(fFeature);
new ol.geom.Point