Generally speaking, the waistband of trousers has two rings. When tying the strap, one end passes through two rings, and then after carefully adjusting the length, one side of the strap passes between the two rings and is adjusted again to ensure comfort.

Cross the two ends of the belt, pass the upper long belt head through the middle of the back belt from the back, and then fold the lower short belt head back. At this point, the longer lead will be wound in front of the shorter lead to form a circle. Finally, drill the long lead out of the previous winding circle and adjust the length by tightening it.

That's my answer.