Free Generators Theorem in Projective General Linear Groups

We desire to obtain conditions for which elements A, B ∈ PGL3 (Fp((x))) will freely generate a free subgroup of PGL3 (Fp ((x))). To get into the above result, we need to consider the action of A and B on P2 by seeing the action of the pre-images of A and B PGL3 (Fp ((x))) in on P2.