How do you add CTAs to an Objective in a Success Plan?

We are exploring the use of Success Plans for onboarding new customers. I have begun to build the plan templates and the objectives inside those templates. I thought I could add/tie a CTA to an objective in a Success Plan, but cannot figure out how to do it. The objective just shows "Tasks (0)". 

Any guidance on this? 

I will admit we are not currently using CTAs or Tasks anywhere else (yet) so this may be a simple question.