JSFiddle - React, Tailwind, and code Playground

HTML

<div class="input-field col s12">
                                <label id="prime" class="active">Prime <span class="red-text">*</span></label>
                            </div>
                            <div class="col s12 input-group"><br>
                                <input type="radio" name="prime" value="prime_oui" id="prime_oui" /><label for="prime_oui">Oui</label>
                                <input type="radio" name="prime" value="prime_non" id="prime_non" checked="checked"/><label for="prime_non">Non</label>
                                <br><br> 
                            </div>
                            <div class="col s12 input-group" id="divCacher" style="display:none;">
                                <div class="input-field col s6" id="divCacher">
                                <input placeholder="Le montant de votre prime, exemple : 1234 ou 1234.67" id="mt_prime" name="mt_prime" type="text" title="Ne peut comporter qu'un nombre entier ou Ă  virgule" class="validate" required>
                                <label for="mt_prime" class="active">Montant de la prime <span class="red-text">*</span></label>
                            </div>
                            </div>

JavaScript

$(function(){
$('#prime_oui, #prime_non').on('click', function (){
        if($('#prime_oui').is(':checked')){
            $('#divCacher').show();}
        else{
            $('#divCacher').hide();
           }
        });
})