index.js

onDeviceReady: function() {
    selectImageBtn = document.getElementById('js-selectImageBtn');
    selectImageBtn.addEventListener('click', function() {
      window.imagePicker.getPictures(
        function(results) {
          let imageURI = results[0];
          PESDK.present(
            function(result){ alert('PESDK result: ' + JSON.stringify(result)); },
            function(error){ alert('PESDK error: ' + error); },
            { path: imageURI }
          );
        }, function (error) { console.log('Error: ' + error); }, 
        { maximumImagesCount: 1 }
      );
    });
}