Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0 while fetching get route

I am trying to fetch a get route from a nodejs api that returns some json data. How ever when I try to make a request to that route, I get this message in my browser console :Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0

Here is the nodejs api code:

app.get('/vusers',(req,res)=>{
console.log("got a request")
return res.json({"message":"hello"})
 })

Here is the reactjs code that makes the request:

 useEffect(()=>{
    fetch('/vusers',{
        headers:{
            'Accept': 'application/json'
        }
    })
    .then(res=>res.json())
    .then(result=>{
        console.log(result)
    })
},[])