Workarounds to have multiple python modules in rplugin/python3 folder

[hp7hao]

Hi, I'm now working on a simple plugin in python, I can't split my code into multiple modules.
If so, it keeps telling me that the module is not found.
And it doesn't work even if I add the module to sys.path.

Is there a workaround to structure your plugin code in multiple modules' manner?

Thanks in advance.