You can't buy a "lifetime license" for the iPad apps; you'll need a monthly or yearly plan.
Search for "Microsoft 365" or individual apps like "Word" in the App Store . how to buy microsoft office for ipad
Open any of the apps and sign in with the email address you used to buy the subscription. You can't buy a "lifetime license" for the
The app will automatically recognize your subscription and unlock all "Premium" features, such as Track Changes and advanced formatting. Family plans? Microsoft Office for iPad and 1TB of cloud storage.
Best for one person. Includes Word, Excel, PowerPoint, and 1TB of cloud storage.