First, make sure you have downloaded the appropriate installer for your Linux environment. If you have not downloaded the installer yet, you may do so here.
You will also need a GoodSync Account to activate your installation. If you do not yet have a GoodSync Account, you can review the tutorial for account creation here.
Finally, make sure that you have added your purchased licenses to your GoodSync account so that they may be used for activation. If you have not yet added licenses to your account, click here for a tutorial.
1) Open localhost:11000 in your browser
2) Enter your GoodSync Account credentials and then select the "License" tab
3) Select the license type and click activate