The step create a test folder for OneSync to see if you like how the app behaves and to judge if everything is working well.
On the OneSync homescreen, click Choose what to sync. after that Click Create test folder pair.
You now have a new folder in your OneDrive account that is synced to your Chromebook. Click OK to continue.
To finish setting up the local folder on your Chromebook, open the ChromeOS Files app. and Navigate to My files > Play Files.
Click the three-dot menu in the upper-right corner and select Show all Play folders.
You should now see a folder called OneSyncFiles. This is the folder OneSync created for sharing files with your OneDrive.
For easy access, right-click the OneSyncFiles folder and select Pin to shelf.
You will then be able to quickly access it from the Pinned Files section in your taskbar.