You can use the 'Client Device' option -
Add a CD or DVD Drive to a Virtual Machine in the vSphere Web Client - Select Passthrough
In ESXi 6.7 the option is "Host Device", under this option you could select the right physical CD/DVD-ROM where you have put your Guest OS installer in your server. Make sure the virtual CD/DVD-ROM is marked a "Connected at power on". Then boot the VM and you could continue from there installing the OS.
Here is the official documentation for 6.7: Configure a Client Device Type for the CD/DVD Drive
Most probably because client device existed on ESXi 6.0 and earlier versions because those host were managed from vSphere client. ESXi 6.5 and above are managed directly from web client hence "Client Device" is eliminated.Cheers Rajeev
VCP6-DCV, VTSP-SV, VSP-SV, MCSE, CCNA