Hi tifsha,
I've updated my answer with screenshots of what a return would look like if it only has a single T4 and someone is in TTO Free. Notice on the Tax Profile Summary, everything is set to None except the Income section.
My payment screen shows that I can file for free.
If this isn't the case for you, please make sure you go through your Profile and ensure that all your sections have nothing checked off except for T4.
