Only 13 members in Asana

I use free version of Asana.
I have only 13 members in my project and I can’t add 2 more.
Could You help me?

Welcome, @Izabela_Król,

Do you have 15 members in your Team? That’s the limit for Asana Basic (free version) and perhaps what you’re running into.

If not, email for help.