access desktop manager through vnc

I am trying a custom project for my personal use. I want to access the desktop manager or GUI running on RPI monitor through VNC. I used various repos and blogs to build this - GitHub - abhimnc/balena-vnc-desktop.
Desktop/GUI is running on RPI fine. Everything is working fine. I can access the RPI through vnc but the desktop screen doesn’t appear in vnc client. It remains blank. Any approaches to resolve this?