How to determine MTU (length of one packet) on NodeJs?

Question

Node.js

I would like to understand how in NodeJs you can determine the length of the MTU packet? Perhaps I didn’t formulate it correctly, but the essence is that, as I understand it, the packet lengths are different for different types of networks (for example, GPON, LAN) as well as types of Internet connections pppoe VPN and so on.

How to implement for me in this case does not really matter, while it is preferable for socket or HTTP or WebSocket (if of course this is possible).