Pages app erases an important document on my iPad

Pages app on 9th generation Ipad has erased an important document. Why?

I am an author. My books are written in Pages on my Ipad. I had recently added a bible quote to the first page of my novel - only to find that next day the whole five chapters were gone! Erased! Not in the deleted items, not on the icloud! I pay 99p a month for Apple storage but now see there is very little of mine on iCloud and most of my Ipad documents are greyed out. What’s going on?

[Re-Titled by Moderator]

Original Title: Pages doc erased