How to validate a jwt in typescript

validate-token.ts

import { Response, Request, Router } from 'express';
import jwt from 'jsonwebtoken';
import jwksClient from 'jwks-rsa';

const router: Router = Router();

const BEARER = 'Bearer ';
const jwkClient = jwksClient({
  strictSsl: true,
  jwksUri: process.env['JWK_URL'] //or wherever you have your configs
});

let cert = "";
/**
 * Anything on this route, will be intercepted by router.use
 * It will try and validate the token
 * if it passes, it will move to the actual method ie router.post('/test-auth'
 * if not it will return a 401 and never hit the end point
 */
router.use((req, res, next) => {
  if (!req.headers.authorization.includes(BEARER)) {
    return res.status(401).send({success: false});
  } else {
    const token = req.headers.authorization.replace(BEARER, '');
    const decoded = jwt.decode(token, {complete: true});
    if (decoded === null) {
      return res.status(401).send({success: false});
    }
    const payload = decoded.payload;
    const header = decoded.header;
    const kid = header.kid;

    jwkClient.getSigningKey(kid, (err, key) => {
      if (err) {
        return res.status(401).send({success: false});
      }
      cert = key.publicKey;
      jwt.verify(token, cert, (err, verfied) => {
        if (err) {
          res.status(401).send({success: false, err: err});
        }
        //if no err we gud
        next();
      });
    });
  }
});

router.post('/test-auth', (req: Request, res: Response) => {
  res.status(200).send({success: true, cert: cert});
});

export const VerifyTokenController = router;

Have you installed the libraries via npm, and are you using ES modules?

it looks to me that you need to install the types ^^
npm i --save-dev @types/jsonwebtoken

For future reference, if you hover over tthe error you will see the answer.

import * as jwt from "jsonwebtoken"