auth.js

// Create middleware for checking the JWT
const checkJwt = jwt({
  // Dynamically provide a signing key based on the kid in the header and the singing keys provided by the JWKS endpoint
  secret: jwksRsa.expressJwtSecret({
    cache: true,
    rateLimit: true,
    jwksRequestsPerMinute: 5,
    jwksUri: "https://" + config.auth0Domain + "/.well-known/jwks.json"
  }),

  // Validate the audience and the issuer.
  audience: process.env.AUTH0_AUDIENCE,
  issuer: "https://" + config.auth0Domain + "/",
  algorithms: ['RS256']
})
router.use(checkJwt)