Set values for Managed Metadata (aka Taxonomy) columns in PowerApps and Flow! (First Release)

Hi, thanks for this update, it's very useful. But I couldn't figure out how to add new values to managed metadata? I have a sharepoint list with managed metadata columns, and using sharepoint default forms, user can add new term if it doesn't exist. When we created powerapps form, user is limited to select from available terms. Is this by design or are we missing something?