Thank you

import VMasker from 'vanilla-masker'

export default {
  data () {
    return {
      form: {
        name: '',
        phone: ''
      }
    }
  },
  watch: {
    'form.phone' (newVal, oldVal) {
      this.form.phone = VMasker.toPattern(newVal, '+9 (999) 999-99-99')
    }
  }
}