JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" value="teste 1 + 1" />

JavaScript

$('input[type=text]').keydown(function(e) {
            // se a tecla pressionada for "+"
            if (e.keyCode == 107) {
              //abre o pop-up
              alert('abre pop-up');
              //limpa o "+" digitado
              $(this).val($(this).val().substr(0, $(this).val().length-1));
              
            }
        });