There is no need to make the order complicated. You can use a tongue scraper before or after brushing if that helps you complete your entire hygiene routine regularly.
A practical option
Clean between your teeth, brush them and then make a few gentle passes with the scraper from the back of the tongue towards the front. You can also start with the tongue; avoiding excessive force matters more.
A scraper is an addition to oral hygiene. It does not replace toothbrushing or cleaning between the teeth.
