questionnaires

This is not a feature that Sensei has currently. There are some quiz timer plugins available if you Google “sensei quiz timer”, e.g.

https://www.wppluginsforyou.com/product/woo-sensei-quiz-timer-plugin/

But I can’t personally vouch for any of them.

Alternatively, you could get in touch with a developer who has previously helped with this kind of feature, e.g.

https://wisdmlabs.com/blog/setting-timer-woocommerce-sensei/

Hope that helps!