Can’t find the Pope in the Bible either!
Actually, you do. See my tag line...
Regardless, Catholics don't do Luther's "Bible alone" thing. That was his invention. At the very least, you'd think it would be in the Bible, not something he just made up.
Catholic doctrine is based on the Authority of Scripture, Apostolic Tradition (2 Thes 2:15) and Church Teaching (Mat 18:17), all of which, ironically, are found in the Bible.