How Do I Get The Discount from PC Purchase?

That offer was only available from April 9 - May 9th per the email sent from Zenimax Online.

If you missed the window it seems the offer is gone for now.

On their forums they have not shown any interest in re-opening the offer.

As long as you have Game Pass, you can play the games included with PC Game Pass without purchasing them individually (you do get a discount if you decide to purchase the games). You also get access to EA Play which includes some EA games you can play without purchasing (games in the vault) and discounts on EA games.

It is the nature of Game Pass that games get rotated after a certain period. This keeps the games offered fresh. You do, as a Game Pass subscriber, get the option to purchase it at a discounted price.

You can't get the discount after it leaves the service. And without notice, how are we supposed to know when to purchase it? I certainly won't purchase a game that I'm paying a monthly fee to play until it's leaving the service.

I think games typically do leave Gamepass at the end of the month. That game could have been an exception?

As for Gamepass discounts;

How do Game Pass discounts on game purchases work?

Xbox Game Pass members can save up to 20% on Xbox One games purchased from the existing catalog, as well as up to 10% off related game add-ons and consumables.

Discounts are based on the Microsoft Store price and on the game’s global launch date. Between 31 and 90 days from a game’s launch date, members receive up to 10% discount off the Microsoft Store price. After 90 days from a game’s launch date, members receive
up to a 20% discount. For game add-ons and consumables, Xbox Game Pass members receive up to a 10% discount from the day the add-on is released.

Game Pass discounts are not combinable with other offers and are not redeemable for cash; discount offers exclude titles within 30 days of launch; discounts are based on Microsoft Store price. Requirements, features, online services, or subscriptions are
subject to change and/or retirement. Discounts are subject to the Microsoft Services Agreement.

I purchased on PC. How do I get it to my Xbox