Mailchannels: Hot to set reply_to to email address from form data

Hi, I am using the mailchannels plugin. I got it working, but I would like to set the reply_to address in personalizations as documented here: https://api.mailchannels.net/tx/v1/documentation to the email address the user supplies in the form. How can this be done? How can the form data be accessed?

Hey there. Did you ever figure this out? Wanting to do the same and maybe customized the subject as well.