When you run the Arduino sketch it changes the state of the driver inputs. An example
digitalWrite(DIRA, HIGH); //one way
digitalWrite(DIRB, LOW);with the Arduino disconnected from the circuit you can do the same with breadboard jumpers. For instance, to do the same as the 2 lines of code above you would connect pin 7 of the driver to 5V, which is the equivalent of pin 3 of the Arduino taking it HIGH and connect pin 2 of the driver to GND, which is the equivalent of pin 4 of the Arduino taking it LOW. You also need to enable the driver by taking its pin 1 HIGH
IMPORTANT NOTE : I am using the values in your sketch and circuit and I have not checked whether they are correct