Form contact in mache template

Hi All,
I don't get something related to the form.

I take the mache template which seems pretty good.
In the skeleton provided , there is a modular page with in it a subpage template contact.

I would like the "contact" in a simple page.

I have first try to duplicate the page from the skeleton and delete all the modular that i don't want.
I keep the contact subpage with :
"title: Contactme
cache_enable: false
onpage_menu: false
content:
items: '@self.modular'
order:
by: default
dir: asc
custom:

• _banner
• _contact
  form:
  action: /home
  name: contact"
  and so on
  In this case, i lost all the header included the menu.

After that i have duplicated the form.html.twig from antimaster to mache in order to create a form page with :
"title: ContactForm
cache_enable: false
onpage_menu: false
form:
name: contact-form
fields:"
and so on
I lost also my header , i still have my menu with a little display default.

Finally, how can i keep all my header ? What i don't get in ?

Thanks for your help.

I am not sure that is the right way but to share one solution, i have had in the form.html.twig :
"{% if theme_config.default_background_image|length > 0 %}
{% for item in theme_config.default_background_image %}
{% set image = item.name %}
{% endfor %}
{% endif %}

<div class="banner banner-alt"{% if image %} style="background-image: url({{ url('theme://images/' ~ image) }})"{% endif %}>
<div class="container">
<div class="row">
<div class="col-lg-12">
<h1>{{ page.title }}</h1>
<span class="line"></span>
<div class="top">{{ page.header.summary }}</div>
</div>
</div>
</div>
</div>
<div class="container">
<div class="row content">
{{ page.content }}
</div>
</div>"