Setup Basics:
Go to Scored Event > Team Scoring

Then select and apply your scoring rules:

Select Delete and Continue:

Select Update Team Types:

And save scored events:

This will enable new Team Report Sections for this Scored Event. To add a new Team report go to Reports > Build Report. Then name the Report, select the Event you're going to add a Report Section for, then select the type of Report Section to add:

To post Team Scoring to RunSignup, you must have a "Team Finisher List" section in a Report which you will be able to auto-save to RunSignup.