For newer versions, Fanuc uses an online portal. If you have a MyFanuc account:
Unlike generic DNC software, the Fanuc tool is optimized for Fanuc’s proprietary communication protocols, including High-Speed Serial Bus (HSSB) and specific Ethernet settings. However, Fanuc protects this software with a license key. Fanuc Program Transfer Tool Serial Number
A serial number for Version 15 work for Version 18. For newer versions, Fanuc uses an online portal