Cannot bind v-model with ion-select

Ionic Framework Ionic Vue
1 
<ion-select

       cancel-text="Annuler"

        ok-text="Confirmer"

        v-model="test"

        required

      >

        <ion-select-option

          v-for="(item, index) in stors"

          :key="index"

          :value="item.name"

        >{{ item.name }}</option>

      </select>

      {{test}}

<script >

//import { useRouter } from "vue-router";

import axios from "axios";

import {

  IonContent,

  IonPage,

  IonInput,

  IonCol,

  IonGrid,

  IonRow,

} from "@ionic/vue";


import { defineComponent } from "vue";

export default defineComponent({

  name: "ProfileDetailsPage",

  components: {

    IonContent,

    IonPage,

    IonInput,

    IonCol,

    IonGrid,

    IonRow,

  },

  data() {

    return {
      test: "???",

    };

  },
...}

Ionic:

   Ionic CLI       : 6.19.0 (C:\Users\Asus\AppData\Roaming\npm\node_modules\@ionic\cli)
   Ionic Framework : @ionic/vue 6.0.1

i don’t know what is wrong ? is there any way to fix it ?