Where do i find the PRO license key to enter into my website?
If the software asks you for license key, you are most probably using old version (ExtraWatch® 2.3)
You must uninstall this version and use most recent version from "Start" section of this website
With most recent version, there is no need for any license key.
You just need to login with email you specified during the purchase.
Then, you should be able to see "PRO version" in header of the application: