grav-plugin-comments/templates/partials/comments.form.html.twig

    <form id="comments-form" name="{{ grav.config.plugins.comments.form.name }}" class="comments-form"
          action="{{ grav.config.plugins.comments.form.action ?  base_url ~ grav.config.plugins.comments.form.action : page.url }}"
          method="{{ grav.config.plugins.comments.form.method|upper|default('POST') }}">

        {% for field in grav.config.plugins.comments.form.fields %}
            {% set value = form.value(field.name) %}
            {% if field.evaluateDefault %}
                {% set value = evaluate(field.evaluateDefault) %}
            {% endif %}
            {% if config.plugins.login.enabled and grav.user.authenticated %}
                {% if field.name == 'name' %}
                    <input type="hidden" name="{{ (scope ~ field.name)|fieldName }}" value="{{grav.user.fullname}}">
                {% elseif field.name == 'email' %}
                    <input type="hidden" name="{{ (scope ~ field.name)|fieldName }}" value="{{grav.user.email}}">
                {% else %}
                    <div>
                        {% include "forms/fields/#{field.type}/#{field.type}.html.twig" %}
                    </div>
                {% endif %}
            {% else %}
                <div>
                    {% include "forms/fields/#{field.type}/#{field.type}.html.twig" %}
                </div>
            {% endif %}
        {% endfor %}
        {% include "forms/fields/formname/formname.html.twig" %}

        <div class="buttons">
        {% for button in grav.config.plugins.comments.form.buttons %}
            <button class="button" type="{{ button.type|default('submit') }}">{{ button.value|t|default('Submit') }}</button>
        {% endfor %}
        </div>

        {{ nonce_field('comments', 'form-nonce')|raw }}
    </form>

    <div id="comments-alert" class="alert">{{ form.message }}</div>