nuxt-promote-yourself/helpers/validators.js

import { helpers } from "vuelidate/lib/validators";

export const supportedFileType = (value) => {
  
  if(!helpers.req(value)) return true
  
  const allowedFormats = ['jpg', 'png', 'jpeg']
  const extension = value.split('.').pop()
  return allowedFormats.includes(extension)
}