Jamboard Interface
If you leave the editing portion of the jam, or leave the app, you will have to click the Edit icon in the bottom right corner to get back into the editing interface.
Save a Jam
Click the three dots in the top-right corner, and choose your method of saving.
Download as PDF - Downloads the entire jam, including all frames (pages) as a PDF.
Save frame as image - Saves the single frame you are viewing as an image file.