XRDP provides better performance than VNC and is easier to set up. It runs on port 3389 by default.
sudo apt update && sudo apt install xrdp
sudo systemctl enable xrdp
sudo systemctl start xrdp
From a Mac, Microsoft Remote Desktop (available free from the Mac App Store) is good to access XRDP servers.
For optimal graphics performance (gaming, etc.), additional setup is required, for example installing mesa-utils and virtio drivers.
Proxmox uses noVNC – HTML5 VNC client running in browser – to provide basic graphical access to its VMs.