Cant setup multilang site

Hello fox
I’m all new to Grav, I realy like it.
But I’m facing an issu for the 10 past hours, I tryed to solved it using AI, but I hope regular old brain might help me better

My problem is about multilanguage FR | EN
Website is monacophotographer.com
I have been changing all the setting I could in sytem.yalm
I have created pages in both language, in the admin pannel I can see both language and select each language
in the folders I have tried mayny combinaison (only 2 at the same time)
default.md
default.en.md
default.fr.md

when I’m in a page in the menu, I can’t swop to the same page in the other language it keep on going back to the home in the default language
I have tried degeug with
PAGE LANGS: {{ page.languages|json_encode(constant(‘JSON_PRETTY_PRINT’)) }}
but I always get PAGE LANGS: null
it looks like both pages are not married together, but in the admin> page they are together.

I have put the change language menu ,
But it keeps putting the active URL in the other language menu
<ul class="lang-switch-manual">
{% for lang in config.system.languages.supported %}
<li>
{% if lang == grav.language.getActive %}
<span class="active" style="font-weight:bold;">{{ lang|upper }}</span>
{% else %}
{# TENTATIVE 1 : La méthode propre (Traductions liées) #}
{% set target = page.translations[lang] %}

                {# TENTATIVE 2 (Secours) : On cherche par le dossier physique #}
                {# On reconstruit l'URL manuellement si Grav est perdu #}
                {% if not target %}
                     {# On suppose que la page FR a le slug du dossier ou son propre slug #}
                     {# C'est une astuce : on force le switch de langue sur l'URL courante #}
                     {# ATTENTION : Cela marchera uniquement si le slug est identique ou si on redirige vers la racine du dossier #}
                {% endif %}

                {% if target %}
                    <a href="{{ target.url }}">{{ lang|upper }}</a>
                {% else %}
                    {# DERNIER RECOURS : On renvoie vers l'accueil de la langue pour ne pas faire de lien mort #}
                    <a href="{{ base_url_simple }}/{{ lang }}">{{ lang|upper }}</a>
                {% endif %}
            {% endif %}
        </li>
        {% if not loop.last %}<li>|</li>{% endif %}
    {% endfor %}
</ul>

If any are used to multi language I hope you will be able to help
All the best
Lawrence

@Lawrence, please help the community help you and read /forum/general/the-art-of-asking-great-questions-t8554

In short:

• show us you read the docs (e.g. https://learn.getgrav.org/17/content/multi-language).
• what are you trying to achieve
• provide proper information/facts like relevant configuration snippets
• show list of extra installed plugins
• versions of Grav and OS
• properly format snippets of yaml, twig, php
• explain shortly the purpose and expected outcome of a twig/php snippets instead of making us trying to understand the code.
• are there any Grav errors?
• are there any errors in the browser's devtools/console?

Asking the community for help starts with investing time in the question... That will hugely increase the probability someone will respond and an answer can be found.