How to correctly send binary messages using websocket from node.js without libraries?

Question

JavaScript

The fact is that I'm trying to implement a dependency free websocket server, I found a couple of articles on this topic in English. and Russian, but in both articles only the processing of "short" text messages is considered, nothing is said about binary ones, unfortunately. And at the moment, apparently, I do not have enough qualifications to understand how to send binary messages (everything is ok with text messages, thanks to articles I can both receive and send them without any problems). That's why I'm asking for help here. If any of you can provide an example of how binary messages are sent, I would really appreciate it. Please do not post links to existing libraries that implement ws in node.js, I tried to look at their sources.