What volume (in milliliters) of 0.170 M NaOH should be added to a 0.140 L solution of 0.021 M glycine hydrochloride (pKa1 = 2.350, pKa2 = 9.778) to adjust the pH to 2.84?

I tried using the Henderson- Hasselbalch equation but I am confused about what to do with the answer to apply it to the question.

After solving 2.84=2.350+log(A-/HA), I got
A- = 0.0158659
HA= 0.0051341