API Modernization

Good afternoon.
There is a ready-made API https://rapidapi.com/vittorio.nardone/api/easy-fast-temp-mail/details
It is required at the site (WP) level to divide the mailboxes received from it into several users depending on their role to display for these users a list of mailboxes, messages, and everything that is mainly the API
Interested in the price and the possibility of such implementation in principle. API can be changed if necessary