Willpower again

Hi, I was asking if there was a podcast on willpower but I never got an answer to this question, rather you gave me a different answer assuming that I want to increase my willpower (or so it seemed to me anyway). I’m not asking because I want to get more of it, I understand that I want to plan using my prefrontal cortex. But.. I want to learn more about willpower, how it works and why we run out of it. So any help/pointers would be appreciated. Other resources are also welcome if there is no podcast on this.