Steps to reproduce the issue

I wanted to create a few custom fields in my article overrides. To achieve this, I was following the instructions posted here (answer 2):
https://joomla.stackexchange.com/questions/21252/joomla-custom-fields-in-category-list?rq=1
The solution wasn't working for me, so I checked the url to the helper file for fields.
Found that there is no 'helper' folder on my Joomla installation.

Expected result

So folder should be present like this : components/com_fields/helpers/fields.php
In my installation it is this : components/com_fields/fields.php

Actual result

Adding custom fields in custom overrides will not work with this method.

System information (as much as possible)

Joomla! 3.9.14 Stable [ Amani ] 17-December-2019 15:00 GMT
Joomla! Platform Version Joomla Platform 13.1.0 Stable [ Curiosity ] 24-Apr-2013 00:00 GMT
Linux dedi2762.your-server.de 4.9.0-11-amd64 #1 SMP Debian 4.9.189-3 (2019-09-02) x86_64
Database Version MYSQL 5.7.28-1
Database Collation utf8_general_ci

Additional comments