You need a pull up resistor to 5V (or a UNO output pin) on RST and SLP (a 1K resistor to +5V is probably best, I doubt you care about sleep mode). If you only want full steps on the motor you could ground the EN, MS1, MS2, and MS3 pins if you want microsteps you would need to connect Uno digital output pins to MS1, MS2, and MS3.
As well you need more connections to the A4988. Basically one end of the push button goes to ground and the other contact connects to both an input pin on the UNO and a pull up resister to +5V. Each push button needs to connect to its own pin on the Uno so the software can tell which of the three is pressed. Your push buttons likely won’t work like that.
