If it's a qualifier and you're on a faster pace than the person you're behind, the race director should let the slower driver know that they should let you by since you're racing the clock and not the other drivers. If it is during the main and you're lapping the slower driver, same thing. If it is a battle for position, it's up to you to find a way to pass. Apply pressure until they make a mistake.
Also, it's up to the passing driver to pass at the opportune time as well. In the middle of a tight chicane isn't the place to do it. It is much safer to let the slower driver go wide on a turn, like a hairpin or sweeper. Better for both drivers.