Login to Playground on a Chrome or Safari browser. You'll see a dashboard similar to the one seen below. Click on the Paperwork tab on the left hand. Click the Forms tab.
From the Forms tab, you'll be able to see your center's forms. In the Status column, you'll see if you've "Not started", are "In progress", or "Submitted" a form.
Click the blue "Complete" button to start or edit a form. Fill out all the required fields (marked with a red asterisks) and any optional fields you'd like. Click "Submit" at the very bottom of the form.
You'll be taken back to the Forms tab where the document will now show "Submitted" and have a submitted date.