const geojson = turf.featureCollection([
  turf.multiPoint([
    [10, 10],
    [-10, -10]
  ])
]);

const polygon = turf.polygon([[
  [0, 0],
  [15, 0],
  [15, 15],
  [0, 15],
  [0,0]
]]);

turf.pointsWithinPolygon(geojson, polygon);

> "Error: coord must be GeoJSON Point or an Array of numbers"