Pretty basic question but I am struggling to find the words to get the correct search result. The soldering iron I bought came with very narrow tips that I think are supposed to be used for circuit boards and components.

When I attempt to solder lines from a USB cord together the line never gets warm enough.

I remember in the past soldering copper lines together from an appliance with no issue so I don't think I'm doing anything wrong in terms of technique but who knows?