The younger your child, the more his or her interpretation of your words is based on the emotional energy they carry — your "vibe" — not the words themselves.
So if your child doesn't listen to your reasonable requests, try this: Listen to yourself as if you didn't know the language and couldn't understand the words; all you have to go by is the tone, the body language, the vibe.
Is it joyful, or heavy? Do you sound eager, or burdened? Does it feel confident, or ambivalent? Is your life a groove, or a grind?
If your vibe is heavy, your joy-oriented child will naturally (and wisely!) tune you out.
Try being silent until you feel centered, connected, and in the Flow. When you speak from that place, you'll emanate an attractive vibe and your child will want to align with you.