Hi, I'm John! I will help you with this.
It can't be link. Microsoft 365 subscriptions purchased through the Apple App Store are managed entirely by Apple. You can confirm this by signing in with your Apple ID and checking Subscriptions in your iCloud settings on an Apple device or online.
Because of this, billing changes, renewals, and cancellations all have to be handled through Apple. You’ll still be able to use Microsoft 365 apps by signing in with your Microsoft account, but the subscription itself will always be controlled by Apple.
I really hope this information is helpful! Let me know if you have any further questions or concerns.
Regards,
John J.D.