If you do not have a commercial license, you can still use Veeam Backup & Replication for free. For Community Edition, you do need to download a license file from the portal. Instead:
If your Veeam server has internet access, you can download the license without opening a browser: download license veeam backup
Downloading the file is only half the battle. You must now install it into the Veeam Backup Console. If you do not have a commercial license,