While editing the document in Teams, if you do not see the options below, please try the steps at the bottom of the article.
Method 1
1. Under Files in Teams, click on the ellipsis>Open>Open in app.
Method 2
Microsoft Word
While editing the document Teams, click on "Editing" at the top, and choose "Open in Desktop App."
Microsoft Excel
While editing an Excel document in Office Web or Teams, at the top of the screen click on "open in Desktop App"
If you do not see the option to open in an Office Desktop App, Check an Office application for updates.
1. Open one of the Office Desktop Apps (Excel or Word, etc.)
2. When the app is open, go to File>Accounts>Office Updates>Update Options>Update Now.
3. Open in a web view a document, and try opening the app again from there.