Unpaid Leave During Resignation

If the Employee Takes Unpaid Leave during Notice Period, can the employer requests the employee to extend his/her notice period?
Yes, the employer has right to extend the notice period

If the employee resigned before confirm, do the employer have to en-cash to annual leave to the empl0yee?
The entitlement is not depends whether you were confirmed or not, but is depend on the length of service with the employment. If you have served more than 3 months of service, you are entitled to the annual leave.