I recommend using Zotero. It’s an app and can sync your citations across iOS and MacOS etc..
I used it on my Mac for my MSc, and there was a word plugin. However, I don’t think word on iPadOS supports plugins.
But Zotero can auto generate in text and full citations based on various different citation styles (think you can make your own too). So you can just copy and paste references.
It works with Safari extensions (on iPadOS) so you can add references directly from Safari. It should save the pdf file of the paper you’re reading too (if there is one).
It’s not the prettiest app, but it is powerful.