Each machine with an installation of ArcGIS Enterprise Builder requires an authorization file for ArcGIS Server Standard or Advanced. You can obtain an authorization file from My Esri (by email, fax, phone, or mail) before proceeding with the installation. Registration requires registration numbers similar in format to ABC123456789. Visit My Esri for more information.
You also need to obtain a portal license file from My Esri, which you'll use when configuring the portal website.