Calling function from one language to other

First you should spend some time to understand how code runs on a computer. I'm talking about the process and thread model.

If you're in python, for example, python the executable is typically compiled code, running as a process. It reads your code as input and based on that, operates the system. It's able to call already compiled/linked C code. Many of python's data structures are implemented in C. It's not possible to dynamically run javascript code using the python executable itself.

You need to have some process running some program which can interpret/compile/run your other code. That could be the same process from your native code, or a different one. If it's a different one, you can use some form of interprocess communication to call/retrieve the output of the execution of the other code.