How do I show the team squads on my stream overlay?

Use Squad bar in Settings → Organizer tools → Overlay: it has three modes, Off, Always and On events. Off keeps the squads off the stream, Always shows them for the whole match, and On events slides them in when a goal, a card or a substitution is recorded, then hides them again. While Squad bar is not Off, Squad position picks where the squads sit, by picture: Bottom, Top, Sides or Center. On events works in every position, not only at the bottom.

For new organizers Squad bar starts Off, so turn it on if you want line-ups on your broadcast. If you set up squads before this option existed, your overlay looks the same as before: a squad bar that was off is now Off, one that was on is now Always in the same position, and the old On events layout became On events at the Bottom.