?php echo get_the_post_thumbnail_url(get_the_ID(), 'full'); code example

Example 1: get featured image url

echo get_the_post_thumbnail_url();

Example 2: wordpress get post thumbnail url

<?php 
  // ALL parameters are optional. Not needed if you are on WP LOOP
  echo get_the_post_thumbnail_url( $the_query->ID, array( 500, 400) ); ?>