How to add an ESX server without VM Monitoring Add-on?

I am trying to add ESX servers to Opmanager (9200). When I add the ESX server using SNMP credentials, I receive this message:

This device been monitored using SNMP, monitoring VMware ESX using SNMP is deprecated from this release. Do not use ESX Server template.

For more details, click here. Please delete this server and use HTTPS credentials to Discover VMWare ESX Server.

But when I try to use VMWare HTTPS credentials, it does not add the server and instead tells me to purchase the VMWare Monitoring Add-on.

I don't need to monitor virtual machines, I only want to monitor the physical ESX server. How do I do this?