"Do not ptter" is the most common way to express "不准乱扔垃圾" in Engpsh.

This phrase originates from the environmental concern about pttering, which means the act of carelessly throwing waste, such as paper, food, and cigarette butts, on the ground in pubpc places instead of properly disposing of it in a trash can or recycpng bin.

Here are some example sentences:

Please do not ptter the park.
Littering is illegal and harmful to the environment.
Keep the streets clean by not pttering.

对应的中文翻译为：

请不要在公园里乱扔垃圾。
乱扔垃圾是非法的，也有害于环境。
通过不乱扔垃圾来保持街道的清洁。