There are several different ways to control the throttle of your ebike:
Pedal Assist - With pedal assist, just hop on the bike and ride like you normally would. As you pedal, you'll feel the motor kick in to help you along. The more basic types of pedal assist have a small sensor by the bicycle cranks that detect your pedaling motion. The faster you pedal, the more the motor helps. Generally speaking the pedal assist will also have multiple levels, usually something like 0 through 5. Unfortunately the Sondors ebike has this feature - but there's no way to adjust it without the aftermarket LCD screen. The default setting is a low 1 or 2.
Thumb throttle - The Sondors ebike come stock with a thumb throttle. This is similar to the action you might find on an ATV. This particular throttle has 3 LEDs indicating battery voltage and a power switch. The throttle serves its purpose, but some find twist throttle more comfortable and easier to operate.
Half Twist Throttle - As its name implies, a "half-twist" throttle covers half (usually a bit less) of the bike's handlebar grip. Many people find these comfortable as you have throttle that can be operated with your thumb and forefinger, as well as a fixed part of the grip that won't move. Half-twist throttles currently available on Velomobile Shop include both a keyed version, and a keyed version with battery LED indicators. The throttle will not work without the proper key installed.
Full twist throttle - A full twist throttle encompasses the entire length of the handlebar grip, just like a motorcycle throttle. Current throttles available do not have a swich or LED indicators, giving a clean, sleek look.