I noticed one answer that was similar, but in my case I used the IIS Configured Editor to find the section I wanted to "unlock".
Then I copied the path and used it in my automation to unlock it prior to changing the sections I wanted to edit.
. "$($env:windir)\system32\inetsrv\appcmd" unlock config -section:system.webServer/security/authentication/windowsAuthentication
. "$($env:windir)\system32\inetsrv\appcmd" unlock config -section:system.webServer/security/authentication/anonymousAuthentication