I'm currently doing a Ph.D. It's standard practice for nearly all PhD programs for the advisor to support a minimal stipend ($15-40k or so depending on the field and university) which goes directly to me, plus university tuition (up to $50k/yr depending on the university) which my lab directly pays my instutition. I only see the tuition bill and that it's paid for me.

Notably, this typically isn't the case for Masters programs, which are cash cows for universities like Stanford and charge $40k/yr+ for students.

Like the other commenter said, any Ph.D. program that isn't covering your tuition and providing a reasonable stipend has huge red flags all over it. They aren't the norm, either.