can unreal charge me 5% for selling physical cars using application?

I am going to build an application in Unreal where I will try to sell my physical cars using this application. I will be re-directing the interested buyers to a checkout page from my website where they pay money for physical cars. If my sale of cars go more than $100 M, is Unreal going to charge me 5% royalty?
All of my money is earned by selling physical cars, I am not selling the application.
Please confirm me on this issue.

This is well beyond the scope of this community. You need to contact Epic Games (probably need custom licensing).