How to get medical leave certificate in Dubai

So guys I tore my ACL while playing basketball and it’s been 15 days since and I was visiting hospital from 5th of this month and this is the first time I am visiting hospital after coming to UAE in 4 years, so doctor asked me to be on bed rest until MRI is done, which is done on last Tuesday and visited doc yesterday so he suggested for surgery which I have to do in a month of a time. Now doc says you can go to office with a brace on but not to put much weight on the knee.

So being first time I thought I can get the medical certificate at the end of my leave and when I requested the hospital for one they said that they cannot issue medical certificate for the past dates, only from today to future dates as DHA portal doesn’t allow them to do so.

My question is how can I get the medical leave certificate other wise, is there any way or did I made a mistake.