Hello.
No, its does not possible.
Booking Calendar plugin possible to install only at the self-hosted WordPress websites.
Kind Regards.
Also do we get access to the source code of the plugin to add our own features?
Yes, you will be able to make your customization.
Disclaimer. Unfortunately we can not start, right now, some personal customization or custom development, because almost have no free time.
Check more about new features here https://wpbookingcalendar.com/faq/need-new-feature/
Thank you for understanding.
Please note, if you will modify the source code of the Booking Calendar, we will not guaranteed the correct work of plugin and do not support it.
