However, John knew that he still needed to obtain a permanent iLO 4 license key. He worked with the advanced support team to troubleshoot the issue and eventually discovered that the server's iLO 4 license key had been lost during a previous hardware upgrade.

This is where many homelab users get stuck. HPE does not sell iLO 4 Advanced licenses anymore. The iLO 4 platform is End of Life (EOL).

He called HP support again and asked for the server's serial number. After providing the server's model and other details, he was able to obtain the serial number.