How do I add a competitor if my campaign is already started?

To add a competitor, go to the settings gear of the Social Media Tracker tool and choose the “manage competitors” option. This will open up the competitors settings.  

Enter the domain of the competitor you would like to add then and click “Add competitor”. You should then see the new addition at the top of the list. Semrush will search for these social media profiles & provide suggested pages.

You may need to manually add these competitors depending on the results. The best way to find your competitor's Facebook page or Twitter handle is to go to their domain and find their social links.