How to restrict the slider in the form so that the radio button has to be checked

Publishing help SEO
1

Hello community, I would like to ask you for help.

How to restrict the slider in the form so that the radio button has to be checked before the next step?

Thank you in advance for your comments.

Regards,

Dominik

Here is my site Read-Only:

https://preview.webflow.com/preview/citya-new?utm_medium=preview_link&utm_source=designer&utm_content=citya-new&preview=7b8fe9db4a5e0e68adbd6a5e34b4bce4&workflow=preview