Hi there!
Slido quizzes are designed for active and live participation so they don’t work well asynchronously. What you could do instead is use a Slido survey that you create with multiple choice polls. You’d have to manually tally up a winner, but you could share a direct link to the survey and let all participants complete at on their own time.

Hopefully that could work for you!

Slido surveys: 

Share a direct link to your survey: