Premium version

Good morning. Dear sirs in support team of WP iCal Availability. I have already bought the premium version.
Please advise me where is located the download link for premium version and how i could get the license key.
We have install the free version and now we need help to install the premium version.
Further to this we run a small rental tourist lodging site with nation booking system.
How can we synchronize the calendar and the rates if possible of our site with the calendar and rates of booking.com, airbnb.com, housetrip.com and tripadvisor.com where we have already registered our small hotel?
Thank you in advance for your help.

https://ww.wp.xz.cn/plugins/wp-ical-availability/