Hi gurp,
Yes, it should be compatible with DIVI. The plugin uses a custom post type for the reservations and a shortcode to output the booking form, so you should be able to integrate it into any site/builder. If you are encountering a specific issue, please let me know.
The payment options are a feature of the ultimate version, discussion of which is prohibited in these forums (https://ww.wp.xz.cn/support/guidelines/#do-not-post-about-commercial-products). If you have any questions about that, please get in touch via our website (https://www.fivestarplugins.com/support-center/).
Thank you!
