You log in to the app and while the Project folders are shown, there are no drawings within the folders.
The common causes for that are:
You are accessing the app on a 2nd or new device
You deleted and reinstalled the app
In the 1st case, you can go back on the old device and upload the work to the ArcSite cloud so you can access them on the new one.
If the 2nd case is true or some other scenario, those drawings likely have been deleted but you can reach out to email@example.com to discuss a solution.