As on this Website explained, there is a 2D Essentials Pack free for all Unity Plus subscribers.
Now I am a Plus subscriber and don’t know how to download this pack.
I am afraid now that this was only a temporary offer?
Updated answer for anyone coming from search:
Essential Packs are seasonal and depending on Unity Plus/Pro subscription date, perks are changing.
Here’s an official answer:
If you purchased your Pro License
during one of the Essentials Packs
promotions, your voucher code should
be in the purchase email. If you’re
not seeing it please reach out to our
The ‘pack’ you are referring is a list of assets from asset store. If you are eligible with the pack, then you should be able to see them in your asset store list.
More information here: https://unity3d.com/pages/essentials-packs
And here: 2D Essentials - Asset Store
If you don’t know how to use Asset Store: Asset Store Basics - Unity Learn