Attaching OneDrive File to Email in Outlook App

I'm using the Outlook mobile app for iOS as well as OneDrive. I'd like to attach files from OneDrive when I compose an email in Outlook, so I click on the paper clip, then choose Attach File, then there is a page titled "Files" and at the top are a list of cloud service providers, such as Google Drive, Box, etc. (picture at the end) Unfortunately there is an X next to each of these, and I accidentally clicked on the X by OneDrive, assuming it was an arrow ">". Now that option has disappeared. Have I permanently lost the ability to attach files from OneDrive to my emails? How do I bring this back? It's not clear to me if this "Files" page is just a part of Outlook, or if it's related to the Files app bundled with iOS. The whole thing is a mess.