If I’m on the waitlist, when exactly do I get off of it?

Long story short, I’m on the waitlist for two classes, Eng Comp 3D and Lifesci 23L. My position is first and second respectively. Both classes have about 18-24 people per section. When can I expect to get off? Should I try to request a PTE number or not?

• This is regarding the spring 23 quarter