The first thing you have to do is make sure that the job is available on the list. But if it is not, you will have to close the game, update it and try again.
The jobs under the occupations appear randomly every time your character searches each year. Instead of waiting for the new jobs to appear next year, you will be able to update the game and prevent your character from getting too old.
In order to become a plumber, you will have to be at least 18 years old, and you will have to get the plumber apprentice job and advance in the career. It shouldn't take long, especially if you make friends with your coworkers and work with them on the many projects available to you. Also, be sure to do the Work Harder option whenever you get the chance.
In this way, we come to the end of this guide on how to become a plumber in Bitlife, so we hope we have been very helpful to you.