After opening your desired project, navigate to Files and select "Add Files".
Here is where you put floor plans, logos, instructions for loading dock, etc. Contract are automatically put here as well and it saves the older versions if you ever need them for reference.)
You may locate the needed file and drag and drop it into the given box or press "Select File" to locate it.
The file will be uploaded. You will be given the options to Tag Location or Tag Clients. This will be done automatically after clicking.
Select the "settings" symbol on the right hand side to manage the file.
Here you can manage the file if needed.