How do I connect iPhone 6S to Lexus RX?

When I go thru the process specified on the car, it gets to a place where it says "enter this code on your phone". But my phone does not offer a keypad on which to type the code. The dealer connected my old 5S to this car, so I know it works if I can figure out what I'm doing wrong. Or I can always go back to the car dealer, I guess.