Using Web Viewer [or other ?] to update a Google Doc via Google Sites

Hi Guys

I’m new to Thunkable and like what I’ve seen so far.

I’ve created an App and downloaded to my Pixel 2 and installed it o.k.

One feature of my App is to use “Web Viewer” to access a Google site that I share for training purposes and the App’s basic access to this site’s URL works fine.

A page on the site contains hyperlinks to some documents I have in Google Drive, that when viewed in a browser [as normal] will launch the documents ready to be viewed or edited.

The above all works fine in the browser but when I access the same site / page from within the Thunkable App and launch a document it displays on screen in ‘read only’ mode.

The ‘edit pencil’ at top of document normally works with an on-screen pop-up saying “Edit with Docs app” followed by 2 options that are (1) NO, THANKS and (2) USE THE APP.

Pressing (1) simply exits the pop-up without doing anything

Pressing (2) has no effect at all. [the button dims slightly, but that’s all]

I can confirm that at the time I am logged into my Google account so I thought I would be able to edit my documents from within the App - maybe this is not possible as 'viewer implies ‘read’ ?

Can anyone confirm if I should be able to use “Web Viewer” in this way to edit, or is it only designed to work for reading ? If the latter is there a different way for me to achieve what I’d like to do ?