Visually change URL with htaccess

I'm trying to visually change

https://ift.tt/1m7FLhW
to
www.example.com/en

but it doesn't work...

Here is my code :

RewriteCond %{QUERY_STRING} ^lang=(\w+)$
RewriteRule ^(.*)\?lang=(\w+)$ /$1 [L]

I don't want any redirection, I just want to see the result on the URL.

Can somebody help me ?

Thanks.