As far as I know, it is naturally formed and does not need practice and study. One thing I personally saw was that one day, my hands and feet trembled, just like nonsense, and it took a while to form! In other words, there was no induction before.
If you want to be immortal, you can make some preparations yourself now, such as not eating beef and dog meat, reading some Taoist books and learning the Eight Diagrams of Zhouyi. When the time is right, you will really become an immortal, and then you will have a foundation, awesome!
Both Taoism and Buddhism can be learned!
But Gong Xianxian doesn't want to realize it, it is automatic, so don't force it!