This is the authenticate.js which will verify the user.

const passport=require('passport');
const LocalStrategy=require('passport-local').Strategy;
const User=require('./models/user');
const JwtStrategy=require('passport-jwt').Strategy;
const ExtractJwt=require('passport-jwt').ExtractJwt;
const jwt=require('jsonwebtoken');

const config=require('./config');

passport.use(new LocalStrategy(User.authenticate()));
passport.serializeUser(User.serializeUser());
passport.deserializeUser(User.deserializeUser());

exports.getToken=function(user){
    return jwt.sign(user,config.secretKey,{expiresIn:3600});
};

var opts={};
opts.jwtFromRequest=ExtractJwt.fromAuthHeaderAsBearerToken();
opts.secretOrKey=config.secretKey;

exports.jwtPassport=passport.use(new JwtStrategy(opts,(jwt_payload,done)=>{
    console.log("JWT payload:",jwt_payload);
    User.findOne({_id:jwt_payload._id},(err,user)=>{
        if(err){
            return done(err,false);
        }
        else if(user){
            return done(null,user);
        }
        else{
            return done(null,false);
        }
    });
}));

exports.verifyUser=passport.authenticate('jwt',{session:false});

exports.verifyAdmin=function(req,res,next){
    User.findOne({_id:req.user._id})
    .then((user)=>{
        console.log("User:",user);
        if (user.admin)
            next();
        else {
            err = new Error('You are not authorized to perform this operation!');
            err.status = 403;
            return next(err);
        }
    },(err)=>next(err))
    .catch((err)=>next(err))
};`

this is user.js /login route where uer can send POST req to login

router.post('/login',cors.corsWithOptions,passport.authenticate('local'),(req,res)=>{
  var token=authenticate.getToken({_id:req.user._id});
  res.statusCode=200;
  res.setHeader('Content-Type', 'application/json');
  res.json({ success: true,token: token, status: 'You are succesfullly logged in!' });

It used to work but now POSTMAN shows UNAUTHORIZED on valid credentials.

It used to work but now POSTMAN shows UNAUTHORIZED on valid credentials.