How to reproduce a Vue2 $listeners behavior on Vue 3?

Hi guys,
I am writing to you because I would like to get some help.

I am migrating an application from Vue2 to Vue3.

In my application, I have a form field of type number, on which I limit the number of characters that can be inserted.

In Vue2, I managed to achieve this, with the help of $listeners, as explained on this link:
=> Custom Events — Vue.js

You can see an example of my code here :

I would like to reproduce this behavior in Vue3; but I can’t figure out how to get an equivalent code for this part:

  computed: {
    inputListeners: function () {
      // see =>
      var vm = this;
      return Object.assign({}, this.$listeners, {
        input: function (event) {

Would it be possible to help me please?
Thank you in advance