If you want to request user agreement in a form, there are two ways to do it.
One way is to drag and drop the T.O.S field on your form and customize it by your desire. You can include an HTML block above the field with your Terms of Service and use some custom CSS to make it look classy, such as in the example below:
Another way is to create a checkbox field that is required and unlabeled. Delete two of the default choices and replace the one remaining with a text similar to I agree with your Terms of Service. Only when that checkbox is checked will users be able to send the form. You can also include an HTML block right below this checkbox, where you will insert a hyperlink that will take users to your Terms of Service.