Have only PURCHASE NOW button on single product page

Hello,
I’m a premium user.
I want to have only one button on the Single Product page, the PURCHASE NOW button that takes the user directly to the Checkout page after clicking on it.
Based on the documentation and some youtube videos I set the premium version so that I have the Purchase Now button in place but the thing is I just want this button shown, and not both. So I want the Add to cart button gone.
How can I achieve this in the settings? Or do I need some code to achieve this?
Please advice.
Peter