The configured username and password should be set in the "Windows Username" and "Windows Password" fields.
If you do not have the aforementioned pre-installed, you can use the following startup script to automatically set up the minimum requirements.
In this example the Windows username is "Build" and the password is "P@ssword2".
See the help file below for Windows private SSH key if you wish to authenticate SSH via keys.
Set-ExecutionPolicy Bypass -Scope Process -Force;
Invoke-Expression ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'));
RefreshEnv.cmd
choco install -y openssh -params '"/SSHServerFeature"'
choco install -y jre8
$username = "Build"
$password = ConvertTo-SecureString "P@ssword2" -AsPlainText -Force
$cred = New-Object System.Management.Automation.PSCredential -ArgumentList $username,$password
Start-Process cmd /c -WindowStyle Hidden -Credential $cred -ErrorAction SilentlyContinue
See the Windows VM Instances documentation for more information.