Taking a Nursing TEAS exam through a PSI Center?

Does anyone have an advice surrounding scheduling a TEAS exam at a PSI center instead of the university testing center? I'm taking my first take in a little under two weeks at Sac State, but the time frame that I want to take my retakes during isn't available since all the testing dates are booked out until September 1st.

I heard that finding testing dates are generally easier when going with a PSI Center, but I'm afraid that I won't find any dates at all. Does anyone have any experience with going with a PSI Center?