Why are krakozyabry displayed from the database?

Question

MySQL

Help to correctly display content from the database, a site on Denver. Encoding - utf8.
I did this:
header('Content-Type: text/html; charset=utf-8');
To get posts:

function get_posts() {
  global $mysqli;
  $sql = "SELECT * FROM posts";
  $result = $mysqli->query($sql);
  $result = mysqli_fetch_assoc($result);
  return $result;
}

And output:

foreach($posts as $post) {
  echo '
  <div class="post">
    <div class="post-author"><a href="/profile.php?id='.$post['author-id'].'">'.$post['author-name'].' '.$post['author-surname'].'</a></div>
  </div>
  ';
}

The following characters come out: � �. The database encoding is utf8_general_ci.
Thanks in advance.

Answer 1

php.net/manual/ru/mysqli.set-charset.php

Answer 2

Change php file encoding to utf8

Answer 3

If as a web server apache2, it can transcode.