I want to add background image fullscreen cover in React JS - html

Question

import React, {Component} from "react";
import CreateRoomPage from "./CreateRoomPage";
import RoomJoinPage from "./RoomJoinPage";
import Room from "./Room";
import { Grid, Button, ButtonGroup, Typography } from "#material-ui/core";
import {BrowserRouter as Router, Switch, Route, Link, Redirect} from "react-router-dom";
import Info from "./info";
I did import image path and local image folder but didn't work.
export default class HomePage extends Component {
constructor(props) {
super(props);
this.state = {
roomCode: null,
};
this.clearRoomCode = this.clearRoomCode.bind(this);
}
async componentDidMount(){
fetch("/api/user-in-room").then((response) => response.json()).then((data) => {
this.setState({
roomCode: data.code
});
});
}
renderHomePage(){
return(
<Grid container spacing={3}>
<Grid item xs={12} align="center">
<Typography variant = "h3" compact="h3">
Xone Music
</Typography>
</Grid>
<Grid item xs={12} align="center">
<ButtonGroup disableElevation variant="contained" color="primary">
<Button color="primary" to="/join" component={Link}>
Join a Room
</Button>
<Button color="default" to="/info" component = {Link} >
<Typography variant = "h5" compact="h5">
?
</Typography>
</Button>
<Button color="secondary" to="/create" component = {Link}>
Create a Room
</Button>
</ButtonGroup>
</Grid>
</Grid>
);
}
clearRoomCode(){
this.setState({
roomCode:null
});
}
render(){
return (
<Router>
<Switch>
<Route exact path="/" render={() => {
return this.state.roomCode ? (<Redirect to={`/room/${this.state.roomCode}`}/>) : (this.renderHomePage());
}}/>
<Route path="/join" component={RoomJoinPage}/>
<Route path="/info" component={Info}/>
<Route path="/create" component={CreateRoomPage}/>
<Route path="/room/:roomCode" render={(props) => {
return <Room {...props} leaveRoomCallback= {this.clearRoomCode} />
}}/>
</Switch>
</Router>);
}
}
I want to add bg image but I don't know how or where to put it.
This page is my landing page.
When I import the local image folder I got some error about webpack.