I have a problem with my api running on http://localhost:8000, I can send data from the react app running on http://localhost:3000. However, I can't receive the data and the request takes around 10 seconds to be received by the server (api). I use axios to send requests. I also receive this request, I guess its a preflight request but I'm not sure : OPTIONS /api/register 204 0.265 ms - 0

This is my code for the request :

submitHandler(e:FormEvent<HTMLFormElement>) {
        e.preventDefault();
        let data = {
          name: this.state.name,
          email: this.state.email,
          password: this.state.password,
          passwordValidation: this.state.passwordValidation,
        }
        console.time("post")
        axios.post("http://localhost:8000/api/register", data).then((res)=>{
          console.log(res.data.errors);
          if(res.data.errors !== null){
            console.log('Error');
            this.setState({errors : res.data.errors})
            return;
          }
          if(res.data.ok){
            this.setState({message : "Succesfully registrated !" })  
            this.setState({toProfile : true}) 
            return;
          }
          console.log(res);
        })
       console.timeEnd("post") //around 10ms
      }
}));
 

This is my Controller :

export function createUser(req:Request, res:Response, next:NextFunction) {
    console.time("createUser")
    const user:any = new UsersSchemaModel(req.body);
    user.password = user.hashPassword(user.password); //around 200ms
    var errors = validationResult(req);
    console.log(req.headers)
    if(req.body == '{}') return res.json({error: "You must provide data"})
    if (!errors.isEmpty()) {
        console.timeEnd('createUser')
        return res.send({ errors: errors.mapped() });
    }else{
        user.save((err:mongoose.Error)=>{
            if(err){
                console.timeEnd('createUser')
                console.log("Error saving user", user);
                return next();
            }
            console.timeEnd('createUser') // around 500ms
            res.json({ok:true})
        })
    }
}

This is my cors options :

app.use(cors({
    origin: ['http://localhost:3000'],
    methods: ['GET', 'POST', 'DELETE', 'PUT'],
    credentials: true, // enable set cookie
}));

Morgan Logs : POST /api/register 200 10021.856 ms - 359

Thanks in advance for any help provided !