For now, Fusion does not have the ability to connect a VM via web browser.
Please see if the VNC connection feature in Fusion can meet your requirement:
1. On Mac host A, power on a VM, open the VM's Advanced Settings, select "Remote display over VNC" checkbox, set VNC password and VNC port (for example: 5901)
2. On Mac host B, from Finder menu, select "Go" > "Connect to Server", in the popup dialog, enter the following address:
vnc://<host A's IP address>:<VNC port, say 5901>
Then click Connect button
3. Input the VNC password when prompted
You will be VNC connected to the VM's desktop.
Please note the host B can be any OS: Windows, Linux and Mac. Mac and some Linux OSes have built-in VNC client, so normally you don't need to install any other application, if host B is a Windows OS, you need to install VNC Viewer or any other VNC client software.
This was exactly what I was looking for. Thank you.