Contact form Multi-Step – Email

Hi,
I have created a multistep form with several steps, using checkboxes, [group group], … and I would like to understand how to ignore in the email sent at the end of the form the fields that have not been selected by the person who made the form.
For example, if the customer selects box 1 and answers the questions, but box 2 has not been checked, I would like that all the elements and sub-elements of this box 2 are not displayed on the confirmation sent by email because it is unsightly and there are many unnecessary lines on this confirmation. Do you have a solution to this? Thanks