postgres command not found

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/9.3/static/server-start.html
Description:

I'm using 9.3, and the documentation says the first thing you should do is
to start the server is type postgres, and ubuntu says command not found

$ psql --version
psql (PostgreSQL) 9.3.18

I saw something that said you're supposed to use psql, but that didn't work
either