Microsoft Teams files are stored in the cloud, by default in dedicated SharePoint sites (for files shared in a team or channel), Office 365 (conversations, notebooks etc) and in OneDrive (for files shared in chats). You can also store your Files in other file storage services such as Dropbox, Google Drive and Box.How do you add apps to Microsoft Teams?
Add an app In Microsoft Teams, select a team, and a channel under that team. In this example, it's the General channel under the Business Development team. Choose + to add a tab. In the Add a tab dialog box, choose PowerApps. Choose Sample apps > Product Showcase > Save. The app is now available to use in the channel.