Fixed Project

src/App.tsx

 import React, { FC } from 'react';
 import { BrowserRouter as Router, Switch, Route } from 'react-router-dom';
-import HomePage from './components/AuthUser/Homepage/HomePage';
+import { HomePage } from './components/AuthUser/Homepage/HomePage';
 
 export const App: FC = () => (
   <Router>

src/components/AuthUser/Homepage/Header.tsx

-import React from "react";
+import React, { FC } from 'react';
+import { AppBar, Toolbar, Button } from '@material-ui/core';
 import { makeStyles } from '@material-ui/core/styles';
-import { AppBar, Toolbar, Button } from "@material-ui/core";
-//import { Home }from "@material-ui/icons";
 
 const useStyles = makeStyles((theme) => ({
-    button: {
-      margin: theme.spacing(1),
-    },
-  }));
-
-const Header = () => {
-
-  const classes = useStyles;
-
-    return (
-
-        <AppBar position="static">
-
-            <Toolbar>
-            <Button
-            variant="contained"
-            //color="primary"
-            className={classes.button}
-            //startIcon={<Home />}
-            >
-              Home
-            </Button>
-            </Toolbar>
-
-        </AppBar>
-
-
-    );
+  button: {
+    margin: theme.spacing(1),
+  },
+}));
+
+export const Header: FC = () => {
+  const classes = useStyles();
+
+  return (
+    <AppBar position="static">
+      <Toolbar>
+        <Button variant="contained" className={classes.button}>
+          Home
+        </Button>
+      </Toolbar>
+    </AppBar>
+  );
 };
-
-export default Header;
\ No newline at end of file

src/components/AuthUser/Homepage/HomePage.tsx

-import React from "react";
-import Header from "./Header";
+import React, { FC } from 'react';
+import { CssBaseline, Grid } from '@material-ui/core';
 
-import { CssBaseline, Grid } from "@material-ui/core";
+import { Header } from './Header';
 
-const HomePage = () => {
-
-    return (
-
-        <Grid container direction="column">
-            <Grid item>
-                <CssBaseline />
-                <Header />
-            </Grid>
-             <Grid item container>
-                 <Grid item xs={false} sm={2} />
-                 <Grid item xs={12} sm={8} >
-
-                 </Grid>
-                 <Grid item xs={false} sm={2} />
-             </Grid>
-        </Grid>
-
-    );
-};
-
-export default HomePage;
+export const HomePage: FC = () => (
+  <Grid container direction="column">
+    <Grid item>
+      <CssBaseline />
+      <Header />
+    </Grid>
+    <Grid item container>
+      <Grid item xs={false} sm={2} />
+      <Grid item xs={12} sm={8}>
+        Content
+      </Grid>
+      <Grid item xs={false} sm={2} />
+    </Grid>
+  </Grid>
+);
\ No newline at end of file