as the title, I want to know the complex representations of the $B(2，\overline{\mathbb{F}_p})$, i.e. invertible upper triangle matrix groups over $\mathbb{F}_p$'s algebraic closure $\overline{\mathbb{F}_p}$...

I know some irreducible representations of this group which can be constructed through Mackey method(B=AH...). But I do not know whether these irreducible representations are the whole irreducible representations. The original Mackey's method was established for finite groups， I don't know whether it can be extended to infinite groups.