Even with a "top" license key, users make mistakes.
Depending on your business size and needs, vCenter 6.7 is available in several versions: vmware vcenter 67 license key top
You can obtain a VMware vCenter 6.7 license key through: Even with a "top" license key, users make mistakes
If you have already purchased a license, you can retrieve or manage your keys through several official channels: How To License vCenter 6.7 Even with a "top" license key
Running 6.7 in production is no longer recommended as it no longer receives security patches or bug fixes.