Error in IIS reserve proxy [Access denied to IP address: undefined]

[imtiazahmeddahar]

I am using expressjs (nodejs) and tried to use this package to filter out IP addresses but getting below error:

Access denied to IP address: undefined

I have also tried proxy option too:

app.set('trust proxy', true);

My configurations:

const whitelistedIPs = [
  "some-ip-address", // Replace with actual IP addresses
  "127.0.0.1",
  "::1",
  
];

const ipBlocker = ipfilter(whitelistedIPs, {
  mode: "allow", //logLevel: "deny"
});

app.use((err, req, res, next) => {
  if (err instanceof IpDeniedError) {
    return res.status(403).send("Your IP is not allowed to access this resource.");
  } else {
    next(err);
  }
});