Hello @IhnatiiM-5451
When you buy a License from Microsoft it is usually linked permanently to you Email or Microsoft account. That’s why you’re not seeing it in your order history at account.microsoft.com — the order record confirms the purchase.
Meaning you would need to have access to the email address to reactivate it later or if you loose the access.
In short
When you buy Windows 11 Pro from Microsoft.com, the product key itself is only sent in the confirmation email, but once you activate it your PC gets a digital license (formerly digital entitlement) tied to your hardware and Microsoft account; that means you don’t need the key again for reinstalls on the same machine because Windows will auto‑activate online, while your order history just shows the purchase record without re‑listing the key, so the email is your responsibility to save if you ever want to transfer the license to another device.
Best regards.
Abhishek