Use the Manage Files tool to upload and organise files associated with your course in an orderly folder structure. Then you can easily add these files to a module in your course using Add from Manage Files.
- Navigate to Content in the navbar of your course.

- Click on the (sub)module you want to place the files to.
- Click on Add File.

- Click More.

- Click on Course File.

- You can now see all files and folders which are located in manage files.
- Click on a file to add this to the module.
When you add files to a module, they will be automatically placed on the bottom of the list.