Adding whatsApp in Extensions, share menu

Dear Friends,

I want to share png files from png preview application to whats-App, i could not able to do this, after opening the file in png preview application, i see a share or upload icon in top right, if i click this icon a range of option pop-up but this do not contain whats-App application as choice. I think, we can add whats-App option in Extensions - Share Menu under system preferences. How to add whats-App application in Extensions - Share Menu?

I want to share png file to whats-App, this i could not able to do since, if i open the share icon in png preview application i could not see the option of Whats-App.

Please Help

Regards