Calculate rotation between 2 points in openlayers using javascript

I'm using OpenLayers with JavaScript, and I'm calculating the rotation between two points (they represent arrows indicating the path taken by a vehicle). I have the following function:

function calculateAngleBetweenTwoPoints(point1, point2) {  let lonLat1 = ol.proj.toLonLat(point1.getGeometry().getCoordinates());  let lonLat2 = ol.proj.toLonLat(point2.getGeometry().getCoordinates());  let angleRad = - Math.atan2(lonLat2[1] - lonLat1[1], lonLat2[0] - lonLat1[0]);  let angleDeg = (angleRad * 180) / Math.PI;  let vector_angle = Math.abs(angleDeg) % 360 ;  vector_angle = (vector_angle * Math.PI) / 180;  return vector_angle;}

Although the orientation is correct for some points, it fails with some points. All points are rendered, I call it here:

function createArrowVectorLayer(points, image) {  const features = [];  for (let i = 0; i < points.length; i++) {      const point1 = points[i];      let point2 = "";      let rotation = 0;      if (points[i + 1] === undefined) {        rotation = 0;      } else {        point2 = points[i + 1];        rotation = calculateAngleBetweenTwoPoints(point1, point2);    }    const arrowStyle = new ol.style.Style({        image: new ol.style.Icon({            src: image,            scale: 0.03,            rotation: rotation,            anchor: [0.5, 0.5],            graphicXOffset: -18,            graphicYOffset: -18,        }),    });    point1.setStyle(arrowStyle);    features.push(point1);}

Does anyone know what is wrong?