Date format?

I’m new to WordPress and not sure if it’s an issue of WordPress version, but my post date was showing the post id instead.
I had to change one line:
https://plugins.trac.ww.wp.xz.cn/browser/simple-feature-requests/trunk/inc/class-template-methods.php#L213
to:
<?php echo get_the_date(”, $feature_request->post->id ); ?>

The reference does say that $format is optional, so maybe I’m doing something wrong.
https://codex.ww.wp.xz.cn/Function_Reference/get_the_date