How do I share source files with my team?

You can share source files in three different ways: 
Assets tab
Drag and drop or browse for your source files and add them to the Assets tab within your prototype: 
InVision Sync
InVision Sync is our free desktop app for Mac. If you’re new to InVision Sync, first download the app
With InVision Sync, your existing prototypes are brought right to your desktop, which means no more uploading screens and assets in your browser. Create a new folder, give it a name, and save your screens and assets directly to their corresponding folders. When you return to your prototypes online, you’ll see your source files in the Assets > Source Files folder.
Shared folder
Use Dropbox, Google Drive, Box, or another shared folder to keep up to date with the latest version of your source file. This option lies outside of InVision.