Screen Sharing and Mouse Control

I am providing teletherapy services for Speech and Language therapy using a platform called Theraplatform.

I have been trying to have my clients use my mouse and make selections when I am sharing my screen with them.

So far they are able to move the cursor on my side but are not able to click or drag on selections. When we are in Theraplatform while screen sharing and the clients have mouse control they are able to click with their mouse.

I believe that the clients are using mostly PCs or iPads. Mouse, track pads, and touch screen have all not worked.

My mac is running OSX El Capitan version 10.11.6