Just wanted to add some information. If you mean logging on the remote Host using its credentials, then you can run the Viewer executable file C:\Program Files\Remote Utilities - Viewer\rutview.exe using command line parameters. For more information please refer to this Documentation article on Viewer parameters: https://www.remoteutilities.com/support/docs/viewer-parameters/
the options you provide for logging in via the command line are great.... but you have added multiple different ways to authenticate to a session but the only command line option you allow is by password.
at a minimum you should provide the ability to login via a username and password.