Required valu for div class fields

Hi

I have site where cf7 form is built differently and can’t figure out how to make this kind of field as required field.

Thank you in advance

  	<label for="business-form-name">Full name</label>
	<input type="text" id="business-form-name" name="FULL_NAME" placeholder="Full name" required />

The page I need help with: [log in to see the link]