The linking process of TrafficStars account to AdSpyglass is a little bit unusual, they ask to fill 4 fields. It looks a bit messy but on practice almost the same.
Login - your TrafficStars login email.
Password - your TrafficStars password.
Client_id - take it in your TrafficStars profile
Secret - take it in your TrafficStars profile
Log in to you TrafficStars publishers panel and find "Client_id" and "Secret" in your profile: