Socket.IO in express.js vs Firebase onSnapshot() in client

Hi,

A part of our app is messaging between users (only a small part of the bigger picture), and I would like to use firebase onSnapshot() directly from the client, since I can subscribe to realtime updates without all the hassle.

If I don't go with onSnapshot in the client, I would have to create a Socket.IO instance in express, which then would do the same action ( onSnapshot() ), to then send it to the client.

We will still implement as much as possible in express using it as a REST api, but in this case it just makes it so much more cumbersome.

So, is it okay to implement it only in the frontend with regards to the course requirements?