Let's see those '10 gardens

I finally got a soil test kit. It tests N-P-K on a scale of 0-4, Depleted to Surplus.
My results are:
Nitrogen 2, adequate but most plants want more
Phosphorus 3.5, plenty
Potassium (K) 0-1, barely readable, big problem
Soil ph is 7.4
How do I fix this?