Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Did you order directly from Microsoft? In that case, you should see your product listed in your Microsoft account.
Most of us have more than one e-mail address that are potential Microsoft accounts. You can test your various @outlook.com, @hotmail.com, etc. addresses at https://account.microsoft.com/services and, with a bit of luck, you'll find the correct one.
If you ordered from a third-party seller, sign in with them and see if you can locate your subscription product.