You can remove init_user() seeing as you don't seem to be using $USER anywhere.

Also if you don't pass in an ID it looks like it would give an internal server error or something weird would happen as you never do anything if $id is undefined.

You also use:

my $table = $DB->table ('Links');

....twice.

Oh one major booboo is your update will update _all_ columns as you don't specify a condition to meet.

my $result = $table->update ( { Link_Status => "$code_returned" } ) or die $GT::SQL::error;