Trending @Infosys; How to get pre approval of exceptional WFH

Currently I am at my home, I had decided to go back office from 18 nov. But I had taphiod now and all my wfh balance is exhausted. I have medical prescription and test report, I want drop an email to extend wfh 1-2 week more, to whom I need to drop mail any idea. Or what can I do.