If you search for "supervisor interview questions" on partner hub you'll find the standard questions. Basically stuff about why you want the role, a challenge you faced and overcame, examples of impact you've made on your store. The big thing you want to do is demonstrate that you're thinking about bigger picture parts of the store, like how to make the store run smoothly, how to ensure a good customer experience for a customers entire visit.

What can you bring to the SSV team? Experience /specific moments with coaching partners and being coached by others? If you have experience as a barista trainer you can tie a lot of the questions into that. Are you good at multitasking? Explaining and understanding the tasks of a supervisor. Why do you want to be a supervisor?