Django crispy forms 'form-inline' doesn't works as expected

Question

I have followed the crispy forms docs to create a simple inline form using bootstarp4. But it seems the form is not becoming a "inline" but a "horizontal".

Here is the code snippet that I have so far along with the screenshot of the rendered web view,

# models.py
from django.db import models


class InlineTestModel(models.Model):
    name = models.CharField(max_length=20)
    age = models.IntegerField()
    email = models.EmailField()


# form_helper.py
from crispy_forms.helper import FormHelper
from crispy_forms.layout import Submit


class FormHelperBase(FormHelper):
    form_inputs = []

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.set_inputs()

    def set_inputs(self):
        for form_input in self.form_inputs:
            self.add_input(form_input)


class TestInlineFormHelper(FormHelperBase):
    form_class = 'form-inline'
    field_template = 'bootstrap4/layout/inline_field.html'
    layout = Layout(
        'name', 'age', 'email'
    )
    form_inputs = [
        Submit('Save', 'Save', css_class='button white')
    ]


# forms.py
from django import forms


class TestInlineForm(forms.ModelForm):
    helper = TestInlineFormHelper()

    class Meta:
        model = InlineTestModel
        fields = '__all__'


# views.py
from django.views import generic
from django.urls import reverse


class TestInlineAddView(generic.CreateView):
    model = InlineTestModel
    form_class = TestInlineForm
    template_name = 'app_name/test_inline_add.html'

    def get_success_url(self):
        return reverse('app_name:success_url')

# template
{% extends 'expenses/base.html' %}
{% load static %}
{% load crispy_forms_tags %}

{% block form_body %}
    <form method="post">{% csrf_token %}
        {% crispy form %}
    </form>
{% endblock %}

Rendered web view

Answer 1

The issue was, we don't need to use <form>...</form> tags while using the crispy tag

{% extends 'expenses/base.html' %}
{% load static %}
{% load crispy_forms_tags %}

{% block form_body %}
    <form method="post">{% csrf_token %}
        {% crispy form %}
    </form>
{% endblock %}

In short, it needs just single line, as

{% extends 'expenses/base.html' %}
{% load static %}
{% load crispy_forms_tags %}

{% crispy form %}