About royalty fee

  1. if we use UE4 to make a product/service A for free to the end user, will the product/service A be charged for royalty fee?
  2. if we also sell product B to the end user for 5000 USD, product B can call product/service A for rendering, will the relevant product B be charged for 5% royalty?
  1. Will revenue be generated at any point (e.g., before the end user)?
  2. This will depend on specific details of implementation. Is A necessary for B?