I'm following a tutorial, and I'm stuck on this problem, The model is not passing data to the MongoDB Atlas Database. I'm trying to post data with Postman, but I get a status 200 ok, but it does not give me a status 201 "user created successfully." I suspect that the Mongoose schema in the model is not correct. I read the Mongoose docs, but I keep having the same problem. here are the code snippets: UserModel.js const UserSchema = new mongoose.Schema({ username: { type: String, required: true, min: 4, unique: true }, password: { type: String, required: true }, }); const User = mongoose.model("users", UserSchema); export default User; fault in UserModel.js; the tutorial says use username:{types:String, etc...}, but I get an error TypeError: Invalid schema configuration: true is not a valid type at path required, and in the mongoose docs it describes that you should use username:{type: String, etc...}, AuthController.js export const signup = async (req, res) => { const { username, password } = req.body; const hashedPassword = bcryptjs.hashSync(password, 10); const newUser = new User({ username, password: hashedPassword }); try { const existingUser = await User.findOne({ username }); if (existingUser) { throw errorHandler(409, "User already exists in database!"); } await newUser.save(); res.status(201).json("User has been created successfully!"); } catch (error) { console.error(error.message); res.status(error.statusCode).json(error.message); } }; Index.js const app = express(); app.use(express.json()); dotenv.config(); app.use(cookieParser()); app.listen(process.env.Server, () => console.log("Server is runnning on port 4000!") ); app.use("/", async (req, res) => { try { res.json("Hello from Mongo server!"); } catch (error) { console.error(error); res.status(500).json("Error:500 Internal server error!"); } }); mongoose .connect(process.env.MongoDB) .then(() => { console.log("successfully Conected to MongoDB!"); }) .catch((err) => console.log(err)); const corsOptions = { origin: function () { if (!origin) return callback(null, true); if (process.env.ALLOWED_ORIGINS) { callback(null, true); } else { callback(new Error("server not allowed by CORS!")); } }, credentials: true, }; app.use(cors(corsOptions)); const __filename = fileURLToPath(import.meta.url); const __dirname = dirname(__filename); const storage = multer.diskStorage({ destination: (req, file, cb) => { cb(null, path.join(__dirname, "public")); }, filename: (req, file, cb) => { cb(null, Date.now() + path.extname(file.originalname)); }, }); export const upload = multer({ storage }); app.use((req, res, next) => { req.upload = upload; next(); }); app.use("/api/auth", authRouter); app.use("/api/post", postRouter); app.use("/api/post/upload", upload.single("file"), postRouterUpload); app.use("/upload", express.static(path.join(__dirname, "public"))); I revised the tutorial twice to see if i didn't make any typo's and read the mongoose documentation on using the proper schema types Continue reading...