Page is not indexed because google select non-www version?

I have just found that google actually choosing non-www version of my site and the www. version / my main page doesn't indexed because of this (it's an landing page)
My question is what causes this since non-www already redirect to www. via cpanel redirect and I didn't see error/mistake on htaccess,and how do I fix this?

Screenshot from search console:

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Are you using any web2.0 platform or it's just a static website. Your 301 redirect may be the use.

alternatesword said:

Are you using any web2.0 platform or it's just a static website. Your 301 redirect may be the use.

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It's static website / landing page

IchBinPersische said:

It's static website / landing page

Click to expand...

Then make sure you did the 301 redirect properly, lots on online checkers there to check.

Here I include the htaccess redirection code for your reference

RewriteEngine On
RewriteCond %{HTTP_HOST} ^yourdomain.com [NC]
RewriteRule ^(.*)$ https://www.yourdomain.com/$1 [L,R=301]

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