How to convert .jar file to .exe file? [closed]

I'm creating a Java program, and I need to test it on Windows. I know how to convert a .jar file to a .exe file on Windows, but the only Windows computer I know of is not mine. My friend will let me test the .exe file on it, but I can't download anything. Meaning no Launchj4. All that I need is an Ubuntu alternative.

Java is known for its write once, run anywhere paradigm.
You probably are able to run the .jar file on windows too (I'm handwaving some minor differences in how a java program executes on each OS here).

It is likely that you can double click the .jar on a windows machine if you have java installed. From the command line, you can use:

> java -jar c:\path\to\your-java-program.jar

However, since this is not the place for windows questions, I'll refer you to this article instead for more details: https://windowsreport.com/jar-file-windows/