Welcome DancingTable,
Given your post, it sounds like you can't save a file in iCloud Drive on your iPad. We'll do our best to solve this for you.
It appears you're using a VPN in your screenshot. This could prevent you from being able to access iCloud. We'd recommend disabling this and restarting your iPad to test it out. Learn more here: Check VPN (Virtual Private Network) and third-party software to help resolve network connectivity issues
With the VPN disconnected, what happens when you attempt to save this file? Are you having the same issues if you visit the iCloud website and save the file? Here's a quick link to check: Sign in to iCloud
Should it persist, did you receive any errors when attempting to upload the file to iCloud on the web? If so, what was that error?
Hoping to hear back, take care.