Ming @ Agents of Speech explains how to potty train by increasing opportunities for success: have your child drink more fluids, sit them on the toilet with books or videos, and reward every win immediately. More chances plus quick praise makes the behavior stick.
Chapters
Is that the child pees inside of the toilet bowl, not in his pants, not in the diaper. Is that you need to keep on making them want to pee. And the only way to do that is to give them water, and that is to keep them on the toilet bowl already. Not tasks, enjoying themselves with, like, books, videos, whatever, like, playing together. You have to increase them as many times. The instances of them doing the target behavior, which is peeing in the toilet. And as they ingest more water, the inevitable will happen, which is water coming out of their body into the toilet. And then you can reward them, okay? Reward them with something really, really, really, really good and acknowledge that they have peed.