More input fields with click

This is not available directly in Contact Form 7. It can be done via custom programing using jQuery.

Hello.
All you need is create fields with name with brackets (<input … name=”data[]” />)
Unfortunately, CF7 can’t parse construction like ([text data[] id:data]), so you have to add brackets via JS.
Example:
[text data class:data] <a href="#" class="add">+</a>

jQuery(document).ready(function($){
  $('.data').attr('name', $('.data').attr('name') + '[]');
  $('.add').on('click', function(e){
    e.preventDefault();
    $('.data:first').clone().val('').appendTo('form');
  });
});

The message will contain your data separated with commas.
This is a simple solution without any validation.