A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Microsoft doesn't make a version of Microsoft 365 for Chromebooks. You are actually using the online version of Microsoft 365, and since you have a paid subscription, you can access more Microsoft 365 features than someone who uses the free version of Microsoft 365 online. To be sure you are getting access to all the features you paid for, sign in to Microsoft 365 by opening any app, then going to File > Account > User Information and entering the username and password of the Microsoft account that purchased the subscription.
Even with a subscription, the online version of Microsoft 365 doesn't have all the features of the downloaded apps, but hopefully it's got what you're looking for.