authentication/api/v1/sessions/Register-Session.ps1

function Register-Session
{
    param(
        [Parameter(Mandatory)]
        [PSCredential] $Credential,
        [Parameter(Mandatory)]
        [string] $AppAlias
    )

    $networkCredential = $Credential.GetNetworkCredential()

    return Invoke-Api Post "/authentication/api/v1/sessions/$AppAlias" -JsonBody @{
        "username" = $networkCredential.UserName
        "password" = $networkCredential.Password
    }
}