An Internet connection is required to activate a license. Product license activation is necessary to generate a Runtime Key for distribution. A license can be activated in one of two ways:
The Dart License Manager.
The cross-platform dotnet-dartlicense tool.
Upon activation your Runtime Key will be displayed for immediate use, and a copy emailed with instructions on its usage.
If you need to retrieve your runtime key at a later date review the following topics:
Finding Your Runtime Key With Dart License Manager
Finding Your Runtime Key With DartLicense Tool