The authentication options for Connect-Swis are:
1. -Username <username> -Password <password>. In this mode, you provide the Orion username and password as plain text strings. If Orion is set up for AD authentication, these can be an AD username/password.
2. -Credential <pscredential>. In this mode you provide a PSCredential object as the parameter. You can get this using "Get-Credential" (which will prompt the user interactively) or by calling "New-Object System.Management.Automation.PSCredential" and passing the username as a string and the password as a SecureString.
3. -Trusted. In this mode your Windows/AD token is used to authenticate with SWIS.
4. -Certificate. In this mode, the CN=SolarWinds-Orion certificate is used to authenticate with SWIS. For this to work, that certificate needs to be present on the machine where powershell is running (this basically means it needs to be one of the Orion servers) and the Windows user running powershell needs to have permission to read that cert's private key, which means the user needs to be a local administrator.