1. After clicking ‘Add New’, place the cursor in the content box and click ‘Add Media’.
2. Click ‘Create Gallery’
3. Select or drag and drop upload (tip: you can drag multiple images into upload) the images you want to add to the gallery and click ‘Create a new gallery’ at the bottom right of the screen.
4. Drag and drop to order if necessary. Make sure the ‘Gallery settings’ in the top right hand corner are set to 'Link to' => 'Media File'. Click ‘Insert Gallery’.
5. Publish the page.