Required fields

Hello, I have just installed this extension and I have a problem:

I said I want to make the field “mandatory” (*), but I tried and it is not, we can validate the contact form without checking the Case. Can you help me ?

Also, I have a hard time managing the design: what css to have the text label aligned in front of the box, and the two aligned left forming a single block with the rest of the contact form?

Thank you for your help c
ordially