How to set Mosaic on the Ubuntu?

Graphics card is RTX4000
Running on Ubuntu 18.04.0.
I have two monitors.
I have installed NVIDIA graphics driver that is 440.82.
Then I want to setting Mosaic of the NVIDIA control panel
But I can’t see anything about Mosaic
So,how to set Mosaic on the Ubuntu?

You mean this?

Option “BaseMosaic” “boolean”

This option can be used to extend a single X screen transparently across display outputs on each GPU. This is like SLI Mosaic mode except that it does not require a video bridge or nvlink bridge connected to the graphics cards. Due to this Base Mosaic does not guarantee there will be no tearing between the display boundaries. On GeForce, Base Mosaic is supported on SLI configurations up to five display devices. On NVIDIA RTX/Quadro, any number of display devices can be used.

Use this in conjunction with the MetaModes X configuration option to specify the combination of mode(s) used on each display. nvidia-xconfig can be used to configure Base Mosaic via a command like nvidia-xconfig --base-mosaic --metamodes=METAMODES where the METAMODES string specifies the desired grid configuration. For example, to configure four DFPs in a 2x2 configuration, each running at 1920x1024, with two DFPs connected to two cards, the command would be:

    nvidia-xconfig --base-mosaic --metamodes="GPU-0.DFP-0: 1920x1024+0+0, GPU-0.DFP-1: 1920x1024+1920+0, GPU-1.DFP-0: 1920x1024+0+1024, GPU-1.DFP-1: 1920x1024+1920+1024"