How to run http post request in vue.js

Question

I'm just learning Vue and I'm making http post request in vue.js and flask as the backend. When I run the program am getting 404 error code. I do not know how to debug the problem but when I test using postman it is working perfect. when I use axios but I am encountering 404.

Below is my frontend code :

<template>
<div> 
    <h3> {{msg}}</h3>
    <p> we help you drive your business with the modern technology. </p>
    <div class="alert alert-success" v-if="isSuccess">
            Post Created Successfully
        </div>
  <form @submit.prevent='OnCreateTown' class="add-town">
    <div class="form-control">
      <label>task</label>
      <input type="text" class ="form-control" v-model="text" name="text" placeholder="name" />
      <input type="number" step="any" class ="form-control" v-model="text" name="text" placeholder="elevation" />
      <input type="text" class ="form-control" v-model="text" name="text" placeholder="grid reference" />
      <input type="number" step="any" class ="form-control"  v-model="text" name="text" placeholder="longitude" />
      <input type="number" step="any" class ="form- control" v-model="text" name="text" placeholder="latitude" />
      <input type="text" class ="form- control" v-model="text" name="text" placeholder="postcode_secto" />
      <input type="text" class ="form- control" v-model="text" name="text" placeholder="nuts_region" />
      <input type="number" step="any" class ="form- control" v-model="text" name="text" placeholder="northing" />
      <input type="number" step="any" class ="form- control" v-model="text" name="text" placeholder="easting" />
      <input type="text" class ="form- control" v-model="text" name="text" placeholder="town_type" />
      <input type="text" class ="form- control" v-model="text" name="text" placeholder="local_government_area" />

    </div>
    <input type="submit" value="submit" class="btn btn-block" />
  </form>
</div>
</template>

<script>
import axios from 'axios';
export default {
    name: 'CreateTown',
    props:{
        msg: String
    },

    data(){ // the data expected from the form
      return{
      form: { 
        name: '',
        elevation: '',
        grid_reference: '',
        longitude: '',
        latitude: '',
        postcode_secto:'',
        nuts_region:'',
        northing:'',
        easting :'',
        town_type:'',
        local_government_area:'',
        isSuccess: false,
        }

      
      };
      
    },
    methods:{
      OnCreateTown(){ // when the submit button is clicked, the form data is sent to the backend
        axios.post('https://david.darwinist.io/proxy/5000/town.json', this.form)
        .then((response) => {// checking response in the console
                    this.isSuccess = true;
                    console.log(response.data);
                    this.$emit('towncreated');
      }).catch(err =>{
        console.log(err)});


      },
      

    },
};

and this is my backend :

def addTown(session, town_dict):
    # Try and get the Country from the database. If error (Except) add to the database.
    town = Town()
    # Add attributes
    town.county = addGetCounty(session,  town_dict["county"], town_dict["nation"])
    town.name = town_dict["name"]
    town.grid_reference = town_dict["grid_reference"]
    town.easting = town_dict["easting"]
    town.northing = town_dict["northing"]
    town.latitude = town_dict["latitude"]
    town.longitude = town_dict["longitude"]
    town.elevation = town_dict["elevation"]
    town.postcode_sector = town_dict["postcode_sector"]
    town.local_government_area = town_dict["local_government_area"]
    town.nuts_region = town_dict["nuts_region"]
    town.town_type = town_dict["town_type"]