Ciao
If you talk about the classic vsphere client that used to be installed on computers to connect to vcenter or esxi hosts, it no longer exists. To access the new versions you have to go there via the web.
if i remember .. The final version of vSphere Client to be released was version 6.0 update 3, which was released in February 2017. Since that time, VMware has moved to an HTML5-based web client. The web client is installed as a part of vCenter Server. It's included with both the appliance and the Windows version.