The app can be downloaded from the Mac App Store. This is a paid app. If you want to try it before you buy it, you can download a demo version.
Easy update process, no license key required, payment via Apple.
Please delete any downloaded demo versions of Export Calendars Pro from your Mac before downloading the app from the Mac App Store. Sometimes the Mac App Store gets confused because it thinks the app is already installed and then the installation fails.
The price depends on your region + sales taxes and is displayed in the respective store. All purchases are one-time purchases (updates included, no additional fees, no subscription).