I posted the same qn before but no one seems to make their own oatmilk.
Anyway, I did find one recipe later, maybe you wanna try it:
4 cups (cold) water
1 ripe banana
2 cups cooked oatmeal
1 tsp vanilla
pinch of salt (optioal)
sweetener to taste (if desired)
Plcae everything in blender and process until smooth, abt 2-3 minutes. Refrigerate. Shake before using.
You may wantto half the amt to see how you like it before making more.