Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Is the product name include the word "Plus"? If so, I believe you purchased that from third party? Microsoft doesn't sell such plan directly to end users because these are "volume license" meant for organizations. Third party vendors resell these at a significant redueced price and they are not supposed to, if you are not an organization user, and you don't have an actual organization IT/admin user to help you in this case. I am sorry. You would have to properly license your Office product.