You must install the vSphere Web Client integration plug-in. With the Web client, you can use a browser to connect to a vCenter Server system and manage an ESXi host.

The Hybrid Cloud Manager is delivered as an open virtualization archive (OVA) file. To install an OVA file, the vSphere Web Client must have the client integration plug-in installed. See the documentation or the video for this task:

Version 5.5u1: Documentation | Video

Version 6: Documentation and Video