How (and is it possible) to write an extension for Selenium?

Question

selenium

Hello Selenium Experts!
I must say right away that I am not familiar with Selenium.
There is a task: it is necessary to send and receive data from the COM port from Selenium. In general, that's the whole task.
How and on what basis are such tasks implemented?
Plugins, extensions are being written?
Is it possible to write a script in python?
Where can you read about it?
Thanks in advance!