Why is my laptop not charging

There could be many issues, what have you checked?

Is the laptop currently on? If currently on, try not to run the battery all the way down until you've found the problem. Some laptops have a battery diagnostic tool built in, try running that by searching for it in windows if u have, or apple.

Battery may be bad. Battery also may have come disconnected or damaged. Check it visually underneath, check also if it is really hot. Try lowering the temperature by turning it off for a while, placing by a fan or A/C. Maybe even some ice under it inside a ziploc back and some paper towels.

Check the charging port for cleanliness. Use qtips to clean and compressed air. Maybe a thin paintbrush or other... check the voltage coming out of the charger with a voltmeter if available.

There could be many reasons, please post more info and answer some of my questions.

Good luck!