Classic / vintage vehicles (=< 3.5t) are subject to the same toll rules that normal cars and not exempted, therefore also need an e-vignette.
All vehicles with a maximum permissible weight of over 3.5 tonnes are subject to the distance based toll system DarsGo.
You can now comfortably order your Slovenian e-vignette here.
Related articles:
What vehicles need a Slovenian e-vignette?
How is the Slovenian vignette checked?
Which roads require a Slovenian motorway vignette?
Can I drive into Slovenia without an e-vignette if I avoid motorways and expressways?