DMT powershell Add New , Update

Hello,

What would be the equivalent in Powershell of running a DMT file with Add New and Update ticked ?

Start-Process -Wait -FilePath $DMTPath -ArgumentList "-User $User -Pass $Pass -Import `"Cash Receipt Combined`" -Source $Source -Add -Update  -ConfigValue $Config"

I am using -Add and -Update but it is not working as expected.