Fetch gives empty response while waiting for long period

I have app made with react and node .

The react app needs to make api call to the node app the node app is running on port 5100 . I am facing problem where I get net_err empty response in the console after waiting long period of time . The thing is my api takes 200s to get the response from the server .

When I hit

http://localhost:5100/api/users/wait-ip

I get response after 200 second But when I hit this in the react app

fetch('/api/users/wait-ip')

I get the following error on console

 GET http://localhost:3000/api/users/wait-ip net::ERR_EMPTY_RESPONSE

This is my function for api

router.get('/api/users/wait-ip',(req,res)=>{
//Others things happen here
 setTimeout(()=>{
    return res.json({
        data:1
    })
},150000)
})

This is the response I get while hitting directly on browser after 150seconds

Any help on how to solve this will be appreciated

from Fetch gives empty response while waiting for long period