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

if (!points) throw new Error('points is required');
    collectionOf(points, 'Point', 'input must contain Points');
    if (!cellSize) throw new Error('cellSize is required');
    if (weight !== undefined && typeof weight !== 'number') throw new Error('weight must be a number');

    // default values
    property = property || 'elevation';
    gridType = gridType || 'square';
    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');
    }