By default, here is the steps:
Prerequisites
■ Verify that you have the Global.Licenses privilege.
■ Ensure that the vSphere Client is connected to the vCenter Server system.
Procedure
- In the vSphere Client, select Home > Administration > Licensing.
- Click Manage vSphere Licenses.
- In the Add License Keys text area, specify license keys one per line.
- You can specify a list of keys in one operation.
- (Optional) Type a brief description of the keys.
- Click Add License Keys.
- If you specify any invalid license keys, you receive an error message that lists only the invalid keys. You can either delete the invalid keys, or add them after correcting them.
- If you are not ready to assign the license keys to assets, click Next through the remaining wizard screens and click Finish to save your changes.
- The license keys are added to the vCenter Server license inventory. If vCenter Server is in a Linked Mode group, the license keys are added to the shared inventory of the Linked Mode group.
Otherwise, please go through below page: (most probably your solution refer to this link - standalone host)