I have a Wordpress site and using Elementor Pro and Woocommerce for on line selling. On the checkout page, I would like to add a custom button to let the users to test their email address and phone number to see if they can receive the confirm email and SMS, so they can be confident to proceed to pay. The email address and phone number should be get from the Woocommerce billing details, not from an extra form field.
The email and sms sending is already working on my site.
Both modifying the Php code or using a plugin are acceptable. I have some system admin skills but know nothing about Php, you are not only going to make it working but also have to teach me how to do it so I can do it myself if anything changes in the future.