How to have C# open a website and run javascript on it

I am trying to make a program that automatically buys items for me I have gotten everything to work, but I am trying to make it so when you click a button it runs java script on a website ex. google.com (basically making it automatic instead of having to do f12 go to console then hit enter).

I have been able to get it to work when I do F12

Not too much to show im stumped on where to start.

I want to make it so (in my C# program) it automatically runs java script on a website when you click a button.