Draft format to ask employee to submit resignation instead giving employee the termination letter

Hello All, I'm working as an hr generalist in proprietor firm. There is an employee who is working for company more than 2.5 years. She took leave for more than one month in which she stated she is not well and going to her hometown for 10-12 days. After seeing the current scenario management has decided to give her the termination.
As an old employee the suggested management to ask resignation from employee instead giving her the termination letter.
Pls help me with the draft wherein i can ask employee in formal way to submit the resignation.

Resignation is a voluntary act of a person or employee.
Asking an employee to submit resignation is an indirect termination without following steps of natural justice.
Best course would be to verbally ask employee to resign if the circumstances are so grim.
From what is written her going on leave seems to be an ecuse to start a thought process of seeking voluntary resignation.