CONN analysis: group comparision after intervention

Dear experts,

The analysis I am trying to perform should show whether a certain intervention shows an effect. We have 2 groups who we want to assume are equal at time point 1. Each group is assigned to an intervention, let's call it "placebo" and "agent". Now I would like to determine whether at time point 2 the "agent" group indeed does show a different connectivity pattern compared to the "placebo" group. Can this be done in CONN, how would I enter this in the second-level/ how would the between-subject contrast and between-conditions contrast need to be defined?

What I have done so far is I have uploaded 2 sessions (time point 1 and 2) for my functional data for every subject, added the functional ROIs I am interested in, entered 2 conditions during the set up step, Tp1 and Tp2 and allocated the subjects according to their group in second-level covariates.

Now how can I determine whether there were changes caused by the intervention, since I need to make sure that any group differences at time point 1 are not accounted for, but only those that appeared after the intervention at Tp2?

I would be immensely grateful for some advise.

Thank you very much!
Meike