You can buy a "drain jetter attachment" for a standard domestic pressure washer. This is a flexible hose with a specialized nozzle that shoots water backward to propel itself forward and blast debris away.
For most standard blockages (leaves, silt, or grease), is the most effective and satisfying solution. It offers the best balance of cost and immediate results. Caustic chemicals are generally a waste of money for outdoor drains, while high-pressure water jetters are the premium "power tool" option if you have recurring issues. how to unblock outdoor drains
Use a bucket or a scoop to remove any debris, leaves, or dirt that may be blocking the drain. Make sure to wear gloves and safety goggles to protect yourself from any sharp objects or dirty water. You can buy a "drain jetter attachment" for