Avatar picture does not display when using get_avatar

The get_avatar function is a pluggable function with it’s first parameter being either the user’s ID or email.

You’re using get_avatar with get_the_author_meta('ID') which should give you the ID of the current user within the Loop.

From the Codex

If used within The Loop, the user ID need not be specified, it
defaults to current post author. A user ID must be specified if used
outside The Loop.

get_the_author_meta( string $field = '', int $user_id = false )

So it would be redundant using get_avatar with get_the_author_meta('ID'), you can just specify the ID directly:

echo get_avatar( USER_ID, 32 );