I have a different solution :
With the help of the Plugin “More Field”, create a new field called, for example, “author rating” with Custom field key “authorrating” and type “number”
Add this field to article only.
Once back in your article, with your new field write your rating according to your max number of stars (1, 2, 3 etc..).
In your theme template, add, for example, this code :
<?php
$ratingauthor = get_post_meta($post->ID, authorrating, true);
$ratingauthor2 = $ratingauthor*24; <strong>(change the 24 according to star size)</strong>
?> <div class="ratingheader" >Rating of <strong>your name</strong> :</div> <?php
if ($ratingauthor <>'') { ?>
<div id="article_rater_915" class="ratepost gdsr-oxygen_gif gdsr-size-24" itemprop="reviewRating" itemscope itemtype="https://schema.org/Rating">
<meta itemprop="worstRating" content = "1">
<meta itemprop="ratingValue" content = "<?php echo $ratingauthor ; ?>">
<meta itemprop="bestRating" content = "6">
<div class="starsbar gdsr-size-24">(change starbar and 24 according to star size and type)
<div class="gdouter gdheight">
<div id="gdr_vote_a915" style="width:<?php echo $ratingauthor2; ?>px;" class="gdinner gdheight">
</div>
</div>
</div>
</div>
<?php }
else
echo "No rating";
?>
</p>
example live :
