Yes, unless you are avoiding all toll roads in Slovenian you will need a valid e-vignette. Even entering a toll road by accident will be directly recognized as violation and penalties apply.
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:
Which roads require a Slovenian motorway vignette?
Can I drive until the first exit on the motorway in Slovenia without a vignette?
Do I need an e-vignette if I only drive in Slovenia once?
What is the DarsGo system (distance based toll)
Does the e-vignette include tunnels like the Karavanke tunnel?