No plank configuration file

I want to manually customize my plank dock, but when I go to the plank directory looking for the settings file, I find only only the launchers directory, and not what I’m looking for. I already searched on some forums, but everybody recommend to use docky or others dock, which are not available for ubuntu 19.04, the version I’m actually using. Does somebody knows how to solve this?

P.S. sorry for the english