Socket.io polling results in 404

[Billyzeim]

I am trying to make a websocket server using socket.io and upon polling I get a 404 error.
This is my next.js server code:
`import { Server } from "socket.io"
import axios from "axios"

export default async function socketHandler(req, res) {

if (res.socket.server.io) {
console.log('Socket is already running')
} else {
console.log('Socket is initializing')
const io = new Server(res.socket.server, {
allowRequest: (req, callback) => {
callback(null, false);
}
})
res.socket.server.io = io

io.on('connection', socket => {
  //JOINING ROOM
  socket.on("join", (data) => {
    socket.join(data.roomname)
    // console.log(data.roomname)
    //console.log(io.sockets.adapter.rooms.get(data.roomname))
    //io.to(data.roomname).emit("event",{type:"population",value: {size: io.sockets.adapter.rooms.get(data.roomname).size, usersinfo: io.sockets.adapter.rooms.get(data.roomname)}})
  });
  //HANDLE MESSAGE
  socket.on("message-to-server", (msg) => {
    // console.log("text:" + msg)
    console.log(msg)
    io.in(msg.roomname).emit("message-to-client",msg)
  });
  //LEAVING ROOM
  socket.on("leave", (roomname) => {
    console.log("leave")
    socket.leave(roomname);
    //io.to(roomname).emit("event",{type:"population",value: {size: io.sockets.adapter.rooms.get(roomname).size, usersInfo: io.sockets.adapter.rooms.get(roomname)}})
  });
  //DISCONNECTING
  socket.on("disconnect", () => {
    console.log("user disconnected");
  });
})

}
res.end()
}`

Many people have not been able to solve this and for me, I could not find any appropriate solution anywhere online either.
I really appreciate any help you can provide.