What proof are parale officers required to obtain for employment verification for parollees in Texas?

My ex does not pay child support and he's over 6 thousand dollars behind. He's on parole and one of the stipulations of his parole is to have a job. He always tells the parole officers that he does handyman work with his brother. But he really doesn't. I'm wondering what parolees are legally supposed to provide provide as proof if it's a requirement of their parole?