How to add a multi-row relationship in the "parent" row

I have this tables:
-Orders
-Products

Every order has to contain multiple products so what I want is:

1- When the user add a new order (through the Show Form Screen action) he will fulfill the differents order fields.
2- after fulfill the orders fields, the user should add products to that new order. The user should be able to add endless products to that order

Is there a way to do that in just one screen? in the data editor which relation should I do?
Thanks!