Double click the code you want to play, and right click on the code and select Copy, or press and hold down the Ctrl button and press C. Then go to Appel v1.4 or Appel+, press the flag, press play, and press load. Then either left click THEN right click on the ask/answering bar, and press paste and submit, or press and hold Ctrl and press P.
Thanks to griffpatch for creating Appel. Appel+ link is there because it cannot be reached with the search bar because the search bar does not count + signs. Also the version number is not the actual version. The number means how many levels there are and I'll update these and reshare so you'll get a notification (if you're following me.)