When you use the language switching option on your site, it doesn't change the URL. If you want Google to index your website in multiple languages properly you MUST use different URLs for different languages. For example you could have:
When you base the language of the page on the geographic IP address of the user or on the user's
Accept-Language header, search engine bots won't be able to crawl both language versions of your site. You can't tell search engine bots to crawl your site twice from different locations or with different
For full details about how to set your site up see How should I structure my URLs for both SEO and localization?.
The inner pages of your site are a little bit better. You have localized the URL path. For example you have
/à-propos-de-nous which serve the same purpose in two different languages. These could be made OK for SEO.