Conditional visibility for form fields

How can we show/hide div in a form depending if a checkbox has been checked or not?

In this example (https://step2you.divhunt.website/inscription-pedagogie-entrepreneuriale), I want to hide the complete block in #2 if the checkbox in #1 is checked, because checkboxes in number 2 are subsets of option in checkbox 1.

Thank you in advance for your help!