This will work:
<?php if ( is_home() ) : ?>
<?php the_post_thumbnail(); ?>
<?php endif; ?>
This code will only show your feature image on homepage and not in post page.
This will work:
<?php if ( is_home() ) : ?>
<?php the_post_thumbnail(); ?>
<?php endif; ?>
This code will only show your feature image on homepage and not in post page.