Pre-purchase The Elder Scrolls Online: Summerset Collector's Edition digitally to receive immediate access to the full base game and the Nightmare Senche Mount, plus get a bonus copy of the Morrowind Chapter for a limited time*
@sudaki_eso
The Elder Scrolls Online: Summerset Digital Collector's Edition should include immediate access to The Elder Scrolls Online base game as you've quoted. If it's not in your friend's PS4 library, they should contact customer support so we can investigate why.