am trying to implement webpack dev server. so install the following package with npm express,webpack-cli. i had issue when running dev server on npm

server.get(“/”, (req, res) => {

10 | const initialMarkup = ReactDOMServer.hydrateToString();
| ^
11 |
12 | res.send(`
13 |
at Parser.pp$5.raise (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:4454:13)
at Parser.pp.unexpected (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:1761:8)
at Parser.pp$3.parseExprAtom (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:3750:12)
at Parser.pp$3.parseExprSubscripts (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:3494:19)
at Parser.pp$3.parseMaybeUnary (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:3474:19)
at Parser.pp$3.parseExprOps (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:3404:19)
at Parser.pp$3.parseMaybeConditional (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:3381:19)
at Parser.pp$3.parseMaybeAssign (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:3344:19)
at Parser.pp$3.parseExprListItem (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:4312:16)
at Parser.pp$3.parseCallExpressionArguments (C:UsersUSERAppDataRoamingnpmnode_modulesbabel-clinode_modulesbabylonlibindex.js:3573:20) {
pos: 302,
loc: Position { line: 10, column: 55 },
_babel: true,
codeFrame: ‘x1B[0m x1B[90m 8 | x1B[39mn’ +
‘ x1B[90m 9 | x1B[39mserverx1B[33m.x1B[39mget(x1B[32m”/”x1B[39mx1B[33m,x1B[39m (reqx1B[33m,x1B[39m res) x1B[33m=>x1B[39m {n’ +
‘
}
[nodemon] app crashed – waiting for file changes before starting…