I can't use form templates

When I click on a form template and try to proceed, nothing happens, it doesn't go on

I checked the same template, according to your screenshot. And I am successfully able to use the template.

I would suggest you, to clear your Browser's CACHE, and try to use the template from this URL: https://www.jotform.com/form-templates/search/opt-in

You can also check the same template on my Demo form: https://www.jotform.com/62554307734962

If you need further assistance, feel free to revert back. Thanks.