I have a doubt. A form is displayed in this twig template.
{% extends 'base.html.twig' %}
{% block title %}Hello CrearUsuarioController!{% endblock %}
{% block body %}
<style>
.example-wrapper { margin: 1em auto; max-width: 800px; width: 95%; font: 18px/1.5 sans-serif; }
.example-wrapper code { background: #F5F5F5; padding: 2px 6px; }
</style>
<div class="example-wrapper">
{{ form_start(form) }}
{{ form_widget(form) }}
<button class="btn">{{ button_label|default('Guardar') }}</button>
{{ form_end(form) }}
</div>
{% endblock %}
so that when you press the save button it sends the data to be modified in the database. But I don't see anywhere to which controller the data has to be sent for it to be processed. How do you know which controller you have to send the data to in that form?
By default the form is sent to the same route where it is located, that is, your controller is in the same route; if you want to specify the path to a different controller you can do so by specifying the path in the form's action.
You can see more information on this site:
https://symfony.com/doc/4.1/form/action_method.html