How do I put all my apps on I cloud as my iPad has not enough storage to update

If your internal storage is full, your only option is to better manage the storage that you have - and delete unused Apps or unneeded data from your iPad. For iOS iPadOS, Apps cannot be run from Cloud or external storage.

These support pages should prove to be helpful:

What's the difference between device storage and iCloud storage? – Apple Support

Manage your iCloud storage – Apple Support

How to check the storage on your iPhone, iPad and iPod touch – Apple Support

Clear Other storage on your iPhone or iPad - Apple Support

Apps work only if they (and their related data) are stored on your device.

Make room on your device's internal storage (it can be checked in Settings>General>iPad Storage):--> How to check the storage on your iPhone, iPad, and iPod touch - Apple Support

Regards

Giulio