How to figure out how many moles of H2 are needed to produce 12.82g of NH3? Can someone solve this for me step by step?

I need step by step instructions to solve this problem. I am confused on how to solve it

1. Write the balanced equation for the reaction.
2. From there, find the mole ratio H2:NH3
3. Find the number of moles of NH3 required from the mass, using the relative mass of NH3.
4. From the mole ratio, find the moles required of H2

Can you show me how to solve it?