Control Guest's permissions in Files tab in Teams

Hi All

I created Azure guest accounts and consultants reported permission denied when accessing the Files tab in the Teams channel. I followed the instructions in this link https://docs.microsoft.com/en-US/sharepoint/change-external-sharing-site and changed from only people in your organization to existing guest users only. Problem solved. The files are accessible in the Files tab. 

Is there a way to set the permission to view only? if so how?