Show Read More button on Astra on Custom Excerpt

/* Append ellipses to excerpts and then show "Read More"  button for manual & automatic excerpts.
* @param type $text
* @return string
*/
function custom_excerpt($text) {
// $text= substr_replace($text,"...",strpos($text, "</p>"),0);
$excerpt = $text . '<a href="' . get_permalink() . '"><button class="read-more-btn" type="button" value="read_more">Read More</button></a>';
return $excerpt;
}
add_filter('the_excerpt', 'custom_excerpt');