How do i add a validation code/ error text to password using vue3 and ionic framework?

i created a password input using vue3 and ionic framework. so now im trying to add a validation code where i have a set value and if the value inputed by the user doesnt match the stored value, then it gives an error msg

<template>
   <ion-input label-placement="stacked" color="primary" expand="block" placeholder="Text" type="password" label="title" >
    <ion-input-password-toggle slot="end"></ion-input-password-toggle>
  </ion-input>
</template>

<script lang="ts">
  import { IonInput, IonInputPasswordToggle} from '@ionic/vue';
//import { eyeOff } from 'ionicons/icons';
  import { defineComponent } from 'vue';

  export default defineComponent({
    components: {
      IonInput, IonInputPasswordToggle},
      setup() {
      },
  });
</script>

any sugesstions on what to add or where to add it?