I purchased Porja Horizon 4 through Microsoft, and my friend purchased Porja Horizon 4 by...

Forza Horizon 4 is cross-play so you shouldn't be having any issues with it

Looking at the version numbers, your version (the Store version) is not an up-to-date version. these are the current version numbers, as per 1st July (after Tuesday's monthly update and the quick fix for Super 7):

https://support.forzamotorsport.net...403539-FH4-Release-Notes-July-1st-2021-Hotfix-

The relevant part is:

1. PC: 1.473.411.2
   
2. Steam: 1.473.411.0
   

You need to go to the Store and check for updates....at a guess, I am taking it that all online features (Auction House, Online MP, Rivals, Clubs etc) are greyed out in your game? That is an indicator that an update is available

Hey Xbox Gamer,

To return your purchase for Forza Horizon 4, please visit our
Refund Request site. Once you will out the form, a refund specialist will take over your request.

try to speak in english or other language then someone can help u (maybe I can)

Hi
FurkanYıldız58,

Thanks for your post! I understand you're experiencing issues with purchasing Forza Horizon 4 on the Microsoft Store. Are you receiving any error messages when attempting to purchase it? You may want to try purchasing the game on the online store:

Forza Horizon 4 - Microsoft Store.

Please keep us updated.

"If you played Forza Horizon 4 through Xbox Game Pass and purchased DLC content for it, worry not: by having an active, full-paid (not discounted) Xbox Game Pass subscription on 6/25 you will be eligible to receive a game token if you have purchased any extra content for Forza Horizon 4 through your Xbox Message Center. Codes will start to be delivered in the following days, please bear in mind that it might take a while before you get your token"

https://forza.net/news/forza-horizon-4-delisting