Open, Edit, and Save Files using the O365 Scope

I am struggling with how to use either O365 or Team scopes to access and manipulate files and folders within Teams folders.

My admin created a registered app in Azure and I have the correct API settings (I belies). In my project I am able to use the O365 Scope and then the Find Files and Folder activity to find and return DriveItem(s). Can loop through them and write their name and other properties. So far so good.

Now I want to grab an arbitrary file (say an excel file) in a particular team. I see the Excel activities under the O365 Scope and the Excel heading. There is no Application Scope there. I can read rows and ranges and so on, and supposedly write to a cell. But I cannot save the Excel?

Does anyone have any code to show an example of doing something like the please???

OK, I have a correction. When I write to a cell, then it is saved, which is great. I wish there were an explicit way to save the excel.

Also, is there any way to reach out and get an item without going through the Files and Folders search? Isn’t there a unique ID for a document so that I can just use that to get the document. And is there any way to know who is logged into the document, the state of sharing, etc.?