The teutons

I played the barbarossa brawl and it said I was victorious . after winning I thought that I would be able to unlock the next challenge . what did I do wrong?

Do you mean the daily challenge?

the one that lasts ten days

So if I understood well you unlocked nothing so far. The first challenges requires you to last at least 10 minutes in the scenario.

If you surrender it says you are victorious. That’s probably a bug though, and doesn’t really count for anything.
If you survived the full 30 minutes, congrats!