Hi Ildar,
I would recommend you to go through the TC8 Licensing Guide that can be found in the Documentation group under TC8 Programs menu shortcut.
In general, you must have License Manager (available as a separate installer from the Customer Portal) installed on some machine that has an access to the internet and is accessible from the virtual machine. When TestExecute starts activation procedure it should be able to find License Manager (otherwise see the mentioned guide for the recommendations on what can be done to make License Manager discoverable) and pass it activation data. Then License Manager will communicate with AQA's site to complete the activation sequence.
In the worst case you may choose to use the manual activation (again, described in the Licensing Guide), but for TestExecute to be able to function the given virtual machine must access the License Manager when TestExecute starts.
Hope this will help.