Setup Open Graph Protocol data by adding this code to the document head.

open-graph-protocol-head-info.php

<?php if ( has_post_thumbnail() ) : ?>
    <meta property="og:image" content="<?php echo get_the_post_thumbnail_url( get_the_ID(), 'large' ); ?>">
    <meta property="og:image:secure_url" content="https://newportshimodablackships.com/wp-content/uploads/2018/06/lanterns-background-1200x630.jpg">
    <meta property="og:image:type" content="image/jpeg">
    <meta property="og:image:width" content="1200">
    <meta property="og:image:height" content="630">
    <meta property="og:image:alt" content="<?php the_title(); ?> - <?php bloginfo( 'name' ); ?>">
<?php endif; ?>