$ResourceGroupName = "rg"
$ServerName = "sqlserver"
$StorageKeytype = "StorageAccessKey"
$StorageKey = "examplestoragekey"
$sqldbs = ("userdb1,userdb2")
$UserName = "sqladminaccount"
$BacpacUri_Stem = "https://example.blob.core.windows.net/sqlbackup/"
$Password = Get-AutomationPSCredential -Name 'MyCredential'
foreach ($sqldb in $sqldbs){
    $BacpacUri = $BacpacUri_Stem + $database  + (Get-Date -Format ddmmyy) + ".bacpac"
    $exportRequest = New-AzureRmSqlDatabaseExport -ResourceGroupName $ResourceGroupName -ServerName $ServerName `
    -DatabaseName $Database -StorageKeytype $StorageKeytype -StorageKey $StorageKey -StorageUri $BacpacUri `
    -AdministratorLogin $UserName -AdministratorLoginPassword $Password
}