The large end of the egg should be where the air sac is located...did you see it somewhere else? Ideally, they're in the air sac now and the tapping is them trying to externally pip. It sounds like ducklings can survive at least 24 hours on the oxygen in the air sac, but if you're not still seeing movement or hearing tapping and it's been 24 hours, you may want to assist. Here's a thread about pipping that you may find helpful:
https://www.backyardchickens.com/t/404803/what-does-internal-external-piping-look-like; that thread touches on assisting, but a really comprehensive guide is here:
https://www.backyardchickens.com/a/step-by-step-guide-to-assisted-hatching.
If you decide to assist, go slowly and assist incrementally (i.e., don't go right to peeling them out of their shells) so they have a chance to fully absorb yolks and blood vessels can dry up. I have assisted in external pipping and zipping, but I try to limit my intervention to creating a zip/crack to make the duckling's emergence easier, not do it for the duckling. Good luck!