JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<form action="">
  <div>
    <label for="inputer">Введи название</label>
    <input type="text" id="inputer">
   </div>
</form>

JavaScript

var input_id = '#inputer';

function def_replacer(val) {
	return val.replace(/--/g, '—');
}

$(document).ready(function() {
	$(input_id).on('input', function() {
  	$(this).val(def_replacer($(this).val()));
  })
});