Add a link.
Upload your photo to a photo hosting site like DropBox, Google Drive or Mega.io
Make sure view permission is set to public and not private.
Click on the photo icon and enter the link as shown on the picture.
Upload an attachment
Scroll down to the Attachments section and attach your photos to the post.
If you are still having trouble, you are welcome to send your photos to nexusdetectors@gmail.com or by WhatsApp 00447923202501 and we can upload them for you.