With a really bad puncture (like a rock slice) your only fallback option is to carry a tube, tire irons, and a way to remove the old (tubeless) valve stem. While this is a hassle, especially since you need to dismount the wheel from the bike, it still beats walking. Make sure you carry a tube large enough to fit your rim. The tire companies will tell you not to put a tube in a tubeless tire, and you should probably listen to them. On the other hand, they never offer to come out and get me when I’m stuck, so I carry a tube.