How to send emails to RT from a react app?

I am a React developer new to working with RT, and struggling to understand how to send emails from our front end app to the RT queues. All of the email services I have used in the past (e.g. EmailJS) handle the larger email hosts like Google, Microsoft etc, but not email addresses that are provided by RT. If anyone can point me in the right direction it would be much appreicated.

We are doing something similar with a public website. All the developers did was have their system email the queue email address and set the “reply to” header to the email address the customer uses. They use their ‘’ address as the original sender address, but RT picks up the ‘reply to’ as the actual sender.