In Retro Bowl, QB mode is a game mode that allows players to control the quarterback and make all the decisions on the field, including passing, running, and audibling. To play QB mode in Retro Bowl:

Choose QB mode from the main menu, select your team and when the game starts, you will control the quarterback. Move the quarterback around the field using the joystick or arrow keys, snap the ball by pressing the snap button, make passing decisions by choosing which receiver to throw to by aiming the cursor at the receiver you want to throw to, press the pass button to throw the ball. You also have the option to run the ball with the quarterback.

Press the button for running and move the joystick or arrow keys to move the quarterback. In QB mode you can call an audible, which allows you to change the play at the line of scrimmage. Press the audible button and select the new play you want to run. As the quarterback, you are responsible for calling the shots on the field, make decisions based on the situation and try to lead your team to victory.

Practice playing QB mode in different situations and in different parts of the field.

Source: https://retrobowl.pro/