Installation of the necessary module:

Install-Module QRCodeGenerator

Complete all needed steps to create a QR Code:

# Allow unlimited execution of scripts
Set-ExecutionPolicy Unrestrict
# Import the module you just installed
Import-Module QRCodeGenerator
# Assign WIFI Variables

$wifissid = <SSID>
$pwd = <password>
$path = "C:\temp"

Create the QR Code:

New-QRCodeWifiAccess -SSID $wifissid -Password $pwd -OutPath $path

Result:

Reference:

https://www.nextofwindows.com/how-to-generate-qr-codes-with-powershell