Click the Print button located in the top right corner of the navigation bar. This will open a new tab with the Print options sidebar on the right side of your screen, along with a live preview of your document on the left.
Toggle the Show answers switch to print the puzzle with the answers already filled into the grid.
Optional: If you would like to print the Grid only, toggle the Show clues switch to hide the clues.
Click the large, blue Print button at the bottom of the Print options sidebar.
From here, you can select your printer, choose to save as a PDF, and adjust standard browser print settings (like portrait/landscape orientation or specific pages).
Click Print (or Save if creating a PDF) in the browser dialog to finish.