The beauty of a drum brake is that it almost never loses it's braking strength, and rarely ever needs to be adjusted. If or when the time comes that you do need to adjust your drum brake though, rest assured it's very simple!
How do you know if you have a drum brake? If you own an Apollo Light or an Apollo City, they both feature a rear drum brake as pictured below:
The Apollo Air Pro also features a drum brake, but on the front wheel instead.
If you're not getting the same braking strength you once were, you can try tightening the silver ring on the back of the scooter circled in red:
You may need to pull back the spring on the brake line to prevent the metal pin from spinning at the same time, but just to turn that metal ring clockwise a couple times to tighten the braking strength.
If you find that the brakes are still not strong enough, you can tighten the knob on the brake lever as well:
The knob on the brake lever is made up of two parts, and you will want to spin both parts counter-clockwise first, and then spin only the wider knob back clockwise until it touches the brake lever again to lock it in place.
This process should not be necessary to do very often, but in the event you need it, you now know how!