Adding User's email field to send mail

How would I add the user’s email to a contact form that was able to be submitted by the front end. I would like to have a button that you click on that takes you to a contact form that you can fill out and automatically goes to the person on the profile.

<?php echo $pu->user_email; ?>

How would I go about that using this plugin,

https://ww.wp.xz.cn/plugins/contact-form-7-dynamic-text-extension/