Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
When the original purchase is through a different provider, you can run into problems when trying to upgrade the subscription.
In your case, because the subscription was purchased through Google Play, any upgrade would need to be done through Google Play, assuming they offer that option. Google is the reseller, so the available upgrade options and purchase terms are determined by Google, not Microsoft.
If you cannot upgrade it through Google Play, you may want to cancel the subscription there and then subscribe directly through Microsoft instead. That may also make the subscription easier to manage going forward.