How do get post thumbnail into plugin?

Question

I want to get post thumbnail into kk Star Ratings. I use this code: <img src="<?php the_post_thumbnail_url(); ?>" />'; But it not working.

I inserted to index.php file, as:

<!-- kksr-stars -->
                <div class="kksr-legend">
                        <img src="<?php the_post_thumbnail_url(); ?>" />';

            $markup .= $this->ratings_as_legend($id);

            $markup .=
                '</div>
                <!-- kksr-legend -->
            </div>
            <!-- kk-star-ratings -->

Answer 1

I dont know where you are using/inserting this code, but maybe you need the current post ID. Try using get_the_post_thumbnail_url( <post-ID> ,<thumbnail-size> );
To get the ID of the current post you can for example use $current_id = get_the_ID();. Than you can try $src = get_the_post_thumbnail_url( $current_id ,'post-thumbnail' ); to get the URL.