You can use the vSphere Web Client to access the ESXi license key.
Procedure
1 | From the vSphere Web Client, connect to the vCenter Server. |
2 | Select the host in the inventory. |
3 | Select the Manage tab. |
4 | Select Settings. |
5 | Select System. |
6 | Select Licensing. |
The license key appears in the form XXXXX-XXXXX-XXXXX-XXXXX-XXXXX.