Which Spotify plugin should I choose?

I am new to Volumio but impressed so far.
I see two plugins in the plugin list: Spotify plugin and Spotify Connect plugin.
What is the difference between them?
The Spotify Connect plugin specifies that a Premium account is needed while the Spotify plugin does not indicate anything of the sort but I have not succeeded in making it work with a free account.

Heya Buje, Welcome to Volumio!

The connect plugin is meant to be controlled from external clients. Spotify Connect - Spotify

While, the other plugin is controlled from Volumio’s WebUI directly.
Unfortunately both plugins won’t work on the free tier.

Thanks a lot