Will My Crested Geckos Tail Grow Back?
No, your crested gecko can drop its tail. But unlike other species' of gecko, unfortunately, once they do, it will not grow back. They can drop their tail as a defense mechanism to distract predators, allowing the gecko to flee to safety. They may even lose their tail if surprised by loud noises or if they feel that you are a predator, sometimes there doesn't seem to be a particular reason that they drop their tail at all.
If your gecko does lose their tail, it doesn't pose any lasting harm to their health, but the act of losing their tail does mean that they were stressed enough to do so in the first place, so you will need to address the issue regarding why your gecko felt stressed enough to lose their tail.
Crested geckos have evolved to live without their tails once they have lost them. Over time your gecko will get used to the fact they have no tail and learn to balance and walk without it. You will need to take care of the tail area where they have dropped their tail and keep it clean to avoid infection.