Pages, Numbers and Keynote on iCloud.com
Pages, Numbers and Keynote are not available on iCloud.com on an iPad. However, you can view documents, spreadsheets and presentations stored in iCloud using iCloud Drive on iCloud.com. To edit files on the web, sign in to iCloud.com on a Mac or Windows computer.
See the Apple Support article Which iCloud.com features are available in the browser on your device.