Plugin causing wp_mail conflict

I am using the Elastic Email Sender plugin on my wordpress site, which uses the Elastic Email API to send mail. Ever since I started using Elastic Email, I have this error at the top of all my pages in the admin dashboard:

wp_mail has been declared by another process or plugin, so you won’t be able to use ElasticEmailSender until the problem is solved.

See screenshot below:

https://picallow.com/elastic-email-conflict/

I deactivated all my plugins one by one to identify the conflict, and it turns out that the error disappears when I deactivate Quick Buy Now Button for WooCommerce by Addify.

I have no idea why, since the plugin does not directly use wp_mail() in any way, but clearly there is some conflict.

I would appreciate any insight into how we can get this resolved.

The page I need help with: [log in to see the link]