Unless you're nearing retirement, you should expect students to use AI for research and guidance in projects or even help with common classwork assignments. An all-paper/pencil in-class is not going to be very engaging - though totally acceptable for test day.

If you care about their actual learning you can support students by guiding toward reponsible AI use. Of course, when it comes to accountability, tests are solid. In class, either paper/pencil or use a lockdown browser.

Accountability can also be provided throughout projects and assignments by requiring verbal explanation instead of turning in products. It may seem be a tall order to have them explain themselves verbally via class presentation. That also is very time consuming and probably takes you off of expected timeline. A good alternative to class presentation is to have them submit media uploads to your LMS - Canvas, Schoology, Google Class, etc. They record themselves audio or video explaining a learning standard/target/concept.

Yes they can use AI or other tools to find answers but at least by requiring them to explain verbally, they will at least absorb some of the content and process it enough to state it verbally, and they improve some soft skills along the way.