Screen Sharing in Gnome Jami

I have installed "Gnome Jami" in my Linux box. It provides text, audio and video chat along with Screen Sharing. The FAQs of the software says that in order to share my screen during call, I have to follow these step: > 1. During a call, right-click on the correspondence screen. > 2. Select the “Screen Sharing” option. > 3. Your screen is now shared. But I cannot figure it out. Right clicking anywhere on the main-screen or chat window or any other place, does not bring Screen Sharing option. If you have used Jami, then kindly guide me about screen sharing in it.