I need help with setting up my robot

I want to use this motor driver:
HiLetgo L293D Motor Driver Shield

I am trying to connect an ultrasonic sensor, but the motor driver takes all the PWM pins besides 44-46 which don't seem to work. I would like to not have to buy anything if possible, and thanks for the help.

Other Info:

  • I am using is an Elegoo Arduino Mega
  • I am using a HC-SR04 Ultrasonic Sensor
  • I have lots of arduino unos and arduino nanos that I could use as well

Why do you think you need a PWM pin for the ultrasonic sensor?