How to trigger click on a button

Question

I\'ve this page. I need to trigger a click on the BUY NOW button on this page using AngularJS.

I\'ve tried these ways to click on this \"BUY NOW\" in content script(

Answer 1

What about Vanilla JS, noone prohibited?

Such as "onlick/click"?

function ae(a,b,c) {
 if (a.addEventListener)
     a.addEventListener (b,c,false);
 else if (a.attachEvent)
     a.attachEvent ('on'+b,c); 
}
function re(a,b,c) {
 if (a.removeEventListener) 
    a.removeEventListener (b,c,false);
 if (a.detachEvent)
    a.detachEvent ('on'+b,c); 
}