Navigating the HPE and VMware websites for this specific image is non-trivial due to paywalls and redirected links. There are two official routes, one requiring an active contract:
For IT administrators maintaining legacy ProLiant or Synergy hardware, finding the correct HPE Custom Image for VMware ESXi 6.7 Update 3 vmware esxi 6.7 u3 hpe custom image download
Since VMware Customer Connect was retired, all downloads are now hosted on the Broadcom Support Portal . Navigating the HPE and VMware websites for this