One or more of the fuel lines may have developed a leak. You should replace the fuel line with a new one instead of attempting to repair the old line.
02 - Worn carburetor bowl gasket
If the leak appears to be coming from the carburetor, it is likely that the carburetor bowl gasket is worn out or missing. You can replace the gasket with a new one to solve the problem.
03 - carburetor float bowl repair kit
Various float assembly components inside the carburetor bowl can be defective as well. The float needle opens and closes the float valve to allow fuel to enter the bowl. If the float needle or the float itself is damaged, the carburetor may continue to fill with fuel until it overflows. You should be able to stop the leaking by replacing one or more of these components.
04 - Damaged fuel tank
The generator’s fuel tank could also be damaged, if the tank has a crack or a small hole, you should replace it instead of trying to repair it.