This is not a stupid question asking members of the forum how to create a multiplayer game. All I want to know is if it is at all possible to make a construct game multiplayer.
Develop games in your browser. Powerful, performant & highly capable.
Not yet, although we have plans to eventually support it.
Would it be possible through external code after export?
If you are good with server side codes, there's a few examples here in the forums of a few members who managed to get multiplayer working, at least on LAN.
Here's a good recent example by Juantar.
If you're a good javascript programmer and want to start making it yourself with WebSockets, you can do so already with the Javascript SDK.