validate_on_submit()在烧瓶中不起作用。我该怎么办？

from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
from wtforms.validators import DataRequired

class MyForm(FlaskForm):
    name = StringField('Name', validators=[DataRequired()])
    submit = SubmitField('Submit')

<form method="POST" action="{{ url_for('submit_form') }}">
    {{ form.csrf_token }}
    {{ form.name.label }} {{ form.name }}
    {{ form.submit }}
</form>

from flask import Flask, render_template, request

app = Flask(__name__)

@app.route('/submit', methods=['GET', 'POST'])
def submit_form():
    form = MyForm()
    if form.validate_on_submit():
        # 处理表单提交逻辑
        return 'Form submitted successfully'
    return render_template('form.html', form=form)

{% if form.errors %}
    <ul class="errors">
    {% for field, errors in form.errors.items() %}
        {% for error in errors %}
            <li>{{ error }}</li>
        {% endfor %}
    {% endfor %}
    </ul>
{% endif %}