url friendly with .htaccess or slug

I'm working with get and retrieving by id, I tried to use the title but unfortunately it does not work, so I adapted the url to have the id and title, so:

/postagem.php?id=69&post-para-front-end

I was trying to do it by .htaccess but it does not work at all, I would like to know a way to change this current url and just leave the title like this:

/post-para-front-end

I'm using usbwebserver, I do not know if that's the reason. follows the schedule.

.htaccess

<IfModule mod_rewrite.c>
  RewriteEngine On

  RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d

  RewriteRule ^contato/?$ contato.php [NC,L]
  RewriteRule ^blog/?$ blog.php [NC,L]
  RewriteRule ^sobremim/?$ sobremim.php [NC,L]
  RewriteRule ^inicio/?$ index.php [NC,L]
  RewriteRule ^$1/(.*)$ /posts.php?id=$2&slug=$1 [NC,L]

</IfModule>

Link on the page that calls the post

<a href="postagem.php?id=<?php echo $dados['id'] ?>&<?php echo slug($dados['titulo'])  ?>"></a>

Slug function

<?php 
function slug($str)
{
    $str = strtolower(trim($str));
    $str = preg_replace('/[^a-z0-9-]/', '-', $str);
    $str = preg_replace('/-+/', "-", $str);
    return $str;
}   
?>