Add Featured Image Column

add_filter( 'manage_posts_columns', function ( $columns ) {

	// You can change this to any other position by changing 'title' to the name of the column you want to put it after.

	$move_after     = 'title';

	$move_after_key = array_search( $move_after, array_keys( $columns ), true );

	$first_columns = array_slice( $columns, 0, $move_after_key + 1 );

	$last_columns  = array_slice( $columns, $move_after_key + 1 );

	return array_merge(

		$first_columns,

		array(

			'featured_image' => __( 'Featured Image' ),

		),

		$last_columns

	);

} );

add_action( 'manage_posts_custom_column', function ( $column ) {

	if ( 'featured_image' === $column ) {

		the_post_thumbnail( array( 300, 80 ) );

	}

} );