How to solve probleme of missing hreflang balise meta in your website

Hreflang Attribute

The hreflang attribute (also referred to as rel="alternate" hreflang="x") tells Google which language you are using on a specific page, so the search engine can serve that result to users searching in that language.

Code Sample
<link rel="alternate" href="" hreflang="en-us" />

What is Rel="Alternate" Hreflang="x"?

Introduced by Google in December 2011, the hreflang attribute allows you to show search engines what the relationship is between web pages in alternate languages. It's useful when you've created content that's specific to a local audience. The hreflang attribute adds a signal to search engines that a user querying in language "x" will want this result instead of a page with similar content in language "y".
For example, if you create a Spanish-language version of your English-language homepage, you would tag it as "Español" by using hreflang="es" so that searchers with an IP address that a search engine has reason to believe is in a Spanish-speaking country are served that page in Spanish instead of the English version. This can decrease your bounce rate and increase your conversions by making sure your target audience lands on the version of your page most appropriate for them.
Hreflang can also be used to show that you have content targeted toward variants of a single language. If that's the case, you can target your pages even more specifically by extending the hreflang attribute with annotations that indicate which region the content is localized for, e.g. Spain (hreflang="es-es") versus Mexico (hreflang="es-mx"). This is particularly useful to geotarget users to control for variations in currency, shipping, seasonality, and culture.
Hreflang is a signal, not a directive. That means that other SEO factors may override the hreflang attribute and cause a different version of your page to rank higher. To give search engines the clearest possible signals about which pages are for users in which language, make sure you're using other international SEO best practices.
Note that while Google and Yandex currently use the hreflang attribute, Bing uses language meta tags instead.

ISO Language and Region Codes

Image from a blog post by Aleyda Solis showing how frequently the wrong hreflang attribute is used.
Google supports the ISO 639-1 format for language codes, and you can get more specific by using the ISO 3166-1 Alpha 2format to signal which region you're targeting. Not all of the codes are intuitive (for example, the code for the UK is "gb" not "uk"), so double check before pasting the wrong code all over your site. This hreflang tag generator can help.

Image from Aleyda Solis's blog post announcing the hreflang tag generator.
You can use multiple hreflangs on one page if you want to show that the page is for users in more than one country or area. For example, if the page targets people who speak Amharic in both Ethiopia and Eritrea, you can indicate that like this:
<link rel="alternate" href="" hreflang="am-et" /> 
<link rel="alternate" href="" hreflang="am-er" />
Don't forget to include a general hreflang attribute without the region code to catch Amharic speaking searchers in Djibouti or other areas of the world that you want traffic from:
<link rel="alternate" href="" hreflang="am" />

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