Ok, I failed to get it before - didn't try to look what I did wrong.
Did a fresh Google.
Foiund this:
https://support.google.com/earth/answer/176160?hl=enhttps://support.google.com/earth/answer/3273767?hl=en&ref_topic=2376762Use of Google Earth Pro requires a valid license key. As of January 20, 2015, Earth Pro licenses are now free. After getting your Earth Pro license, you can register, download, install, and sign in to start using Earth Pro's advanced features.
Earth Pro system requirements
PC: Windows XP, Windows Vista, or Windows 7
Mac: Mac OS X 10.6.0 or later
About licenses
To get a free Google Earth Pro license, complete this form (
https://geoauth.google.com/gev0/free_trial.html) and we will send you an email containing a license key. Existing license keys have already been extended, so if you already have a license then you can keep using Earth Pro without ever needing to renew again.