How to prevent a group of users downloading SharePoint and MS Teams documents

Hi All,

We need to prevent a group of users downloading files from SharePoint, and MS Teams. We want them to be able to access and edit the files using office online, but not download and edit them locally.

We have been able to do this for Outlook using these instructions https://www.b-fortyone.com/single-post/2016/06/07/Office-365-Prevent-downloading-attachments-via-Outlook-Web-App but we cannot do it for the SharePoint and MS Teams. 

I hope you can help
Colin