How to use the @turf/hex-grid function in @turf/hex-grid

weight = weight || 1;

    var box = bbox(points);
    var grid;
    switch (gridType) {
    case 'point':
    case 'points':
        grid = poinGrid(box, cellSize, {units: units, bboxIsMask: true});
        break;
    case 'square':
    case 'squares':
        grid = squareGrid(box, cellSize, {units: units});
        break;
    case 'hex':
    case 'hexes':
        grid = hexGrid(box, cellSize, {units: units});
        break;
    case 'triangle':
    case 'triangles':
        grid = triangleGrid(box, cellSize, {units: units});
        break;
    default:
        throw new Error('invalid gridType');
    }
    var results = [];
    featureEach(grid, function (gridFeature) {
        var zw = 0;
        var sw = 0;
        // calculate the distance from each input point to the grid points
        featureEach(points, function (point) {
            var gridPoint = (gridType === 'point') ? gridFeature : centroid(gridFeature);
            var d = distance(gridPoint, point, units);