https://forum.joomla.org/viewtopic.php?t=969543

 

This calls custom field functions:
It should be placed after "defined('_JEXEC') or die";

CODE: SELECT ALL

JLoader::register('FieldsHelper', JPATH_ADMINISTRATOR . '/components/com_fields/helpers/fields.php');

This cycles through all fields:
Place this code after foreach loop in module:

CODE: SELECT ALL

 $fields = $item->jcfields ?: FieldsHelper::getFields($context, $item, true);	
    foreach($fields as $field){
        if ($field->value){
            $item->fields[$field->name] = $field;
        }
    }

And this renders specified field data:

CODE: SELECT ALL

echo $item->fields['my-field-name']->value;

If someone has better solution, like how to get classes rendered as well, fell free to post it here.