Greetings Mukesh,
you have to upload the desired picture(s) by yourself on an external hoster like: imgur.com/
Feel free to google some provider, which fits best to your requirements. After uploading, you just have to copy and paste the direct image link into the "Message"-Box / -field.
With a space character within the link (just to show you how it would work, without letting it transform directly into picture displaying):
ht tp://i.imgur.com/wGZNERP.jpg
And without a blank, it looks like explained:
Please let us know, if any questions are left.