That linked article doesn't help. It just tells you to use methods that no longer seem to appear in Teamviewer v13.1.3629 H (as of 6/11/18)... Actually I discovered how to do it: You have to click on the blue & white Teamviewer box in the lower right corner on the computer you're controlling (extend it if it's slid in). The middle button looks like 'two pages', click that and a row that says 'File box' will open. You can then drag files to it to send to yourself. At the right end of that row is a Gear button, click that to open a dialog box to select & send a file from your computer to the remote one.
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