How to use multiple monitors with Microsoft Remote Desktop

Create a shortcut for RDP using MSTSC, this will be a .RDP file

To list your monitors (I have four)

mstsc /l

Edit the MSTSC shortcut (.RDP) file in NotePad, add the following lines (first line number 0,4 depends on how your monitor are setup, for me 0,4 uses the middle and left monitor).

In my case line span monitor was missing.

selectedmonitors:s:s:0,4
screen mode id:i:2
span monitors:i:1
use multimon:i:1

Save and test.

This is the full MSTC save file saved as .RDP :

First line full address change the IP or use Hostname

full address:s:192.168.1.100
selectedmonitors:s:s:0,4
screen mode id:i:2
span monitors:i:1
use multimon:i:1
desktopwidth:i:1920
desktopheight:i:1080
session bpp:i:32
winposstr:s:0,1,208,19,1712,1155
compression:i:1
keyboardhook:i:2
audiocapturemode:i:0
videoplaybackmode:i:1
connection type:i:7
networkautodetect:i:1
bandwidthautodetect:i:1
displayconnectionbar:i:1
enableworkspacereconnect:i:0
disable wallpaper:i:0
allow font smoothing:i:0
allow desktop composition:i:0
disable full window drag:i:1
disable menu anims:i:1
disable themes:i:0
disable cursor setting:i:0
bitmapcachepersistenable:i:1
audiomode:i:0
redirectprinters:i:0
redirectcomports:i:0
redirectsmartcards:i:1
redirectclipboard:i:1
redirectposdevices:i:0
autoreconnection enabled:i:1
authentication level:i:2
prompt for credentials:i:0
negotiate security layer:i:1
remoteapplicationmode:i:0
alternate shell:s:
shell working directory:s:
gatewayhostname:s:
gatewayusagemethod:i:4
gatewaycredentialssource:i:4
gatewayprofileusagemethod:i:0
promptcredentialonce:i:0
gatewaybrokeringtype:i:0
use redirection server name:i:0
rdgiskdcproxy:i:0
kdcproxyname:s:
drivestoredirect:s:

It seems that the Microsoft Remote Desktop app does not support Multiple screens

https://learn.microsoft.com/en-us/azure/virtual-desktop/compare-remote-desktop-clients

Yes, how do you enable multiple monitor support for the Windows Remote Desktop Client App, from the Microsoft Store?