Upload and notify
On the Documents page of a task, click the "+Document" button to reveal the add documents panel. Select or drag-and-drop files from your computer to the panel.
After the files are uploaded, a dialog box will appear where you can comment on the upload and select people that you wish to notify. You can notify project members directly or notify others by email. Notifications will be sent immediately after you click “Add”.
Comments and notifications will be recorded under the corresponding Activity tab for the project and the task.
Share a document already uploaded
If you wish to share a document that has already been uploaded, click on the (...) button, and select "Share". Like with new uploads you will be able to select people to notify and write a comment.
If you only need to copy the document link, select "Get a link" from the same action list.