By default, Natural HR provides a facility to add benefits such as Pension, Medical insurance, Life assurance etc to an employee profile by going to 

Administration > Company > Settings > Company settings

and then in the 'Financial' section, 'Benefits module' is set to 'Simple'

To add a benefit to an employee go to

People > Employees

and then click on the 'Benefits' action. You can add any benefits either as numeric or text values

These benefits can be viewed by the employee by going to 

Self service > My details > My total rewards

You can create additional benefits to add to your employee records by going to 

Administration > Company > Custom benefit types

Here you can add up to 12 additional custom benefit types. After entering a name for your custom benefit(s). Please take note of the warning banner information.

After clicking on 'Submit' to save the new Custom benefit type(s) you can return to the 'Benefits' action on the employee record and then add a value or text to the new benefit like this

After clicking on 'Submit', the new custom benefit will be shown in the employee's My total rewards view

and using the 'Employee benefits' data source, you will also be able to report on these custom benefit types. You will see them listed in the Employee benefits fields section as Custom benefit 1 to 12, after adding the field you can edit the column name as shown here, where 'Custom benefit 1' is renamed to 'Company wellness program'

so that when you run the report, the custom benefit(s) you added will be reported like this