From my understanding, one party (the plantif), will get the original FJ, while the other party, will get another copy.
Not sure if it's certified true copy though. Not sure if via email? Since usually is post mail in the past. Maybe is email now due to covid? You may need to check with law firm for it.
But I think the period depending on law firm/court etc. May not be exactly 3 months. Can be earlier or later.
8 yrs ago for mine case, I received the certified copy thru mails. U need the original copy because for any reason, i.e ur company HR (if u already declare marriage to company) and ur future marriage, u need it. Do note that ROM will only registered ur marriage and the record is craved on stone. If u remarriage, the original or certified true copy need to be presented. Maybe can contact the Law firm to get a copy via mail