Canadian Version Sage 100 Contractor 2019 (22.4.37.0) Canada payroll release 2021.1

Some of my employees have identified they would like to pay an additional amount per pay for Income Tax.  However, Sage will only deduct the amount prescribed by their TD1 - Claim Code 1 (which is the highest default for income tax deduction).  It is not populating additional income tax amount for the employees.  How can I get Sage to deduct this extra tax per employee?  I do not wish to make a manual transaction for all the employees on every pay cheque.  Maybe the employee needs to be salary; maybe hourly; is there another Code I can create?  I need to be sure that if I deduct additional income tax from an employees pay cheque, that the additional tax amount is added to their T4 as well.   The Sage support guy could only advise a manual entry.  I've been working on this for 2 weeks but have not found a solution.  Thanks in advance.