import (
	"github.com/whosonfirst/go-whosonfirst-image"
	"image/png"
	"io"
	"os"
)

func main() {

     	path := "/path/to/feature.geojson"

	r, _ := os.Open(path)
	defer r.Close()
	
	body, err := io.ReadAll(r)

	opts := image.NewDefaultOptions()
	img, _ := image.FeatureToImage(body, opts)

	png.Encode(opts.Writer, img)
}

./bin/wof-feature-to-png /usr/local/data/whosonfirst-data-constituency-us/data/110/874/663/7/1108746637.geojson > 1108746637.png