@Single123
I don't quite get why you need the passports.
You can't leave the country with your kids without his permission (i presume you're not going to), as that'd be the best way of losing custody/residency.
How can you seriously not understand why a person with children in danger from their partner and planning to leave would need passports?
Lots of reasons - he could take them either to remove children from whichever country they are in or for the power that holding identity documents from someone gives. We don't know where OP is in relation to her nationality. She could be in a foreign jurisdiction and want to return home to her parents/family/place of birth with her children. & lets face it if its a question of getting away and out to a safe place or be murdered, leaving a country without "his permission" could be the best thing to do. And it doesn't follow "that's the best way of losing custody/residencey" because that entirely depends on the factual situation and the laws of both countries involved.
More importantly, if OP is in danger such that she wants to leave and re-start a life a fresh in safety, she will need passports to open a bank account, rent a place, get utility bills and so on.
In general terms if you are dealing with an abusive violent and controlling person and you plan to leave, you need to get everything you need (bank cards, drivers licence, other identity documents like birth certificates, passports, any utility bills or bank statements or documents in your own name that places need to establish who you are ) out of the house because these documents can be held to ransom and make it a 100 times more difficult to establish yourself in a place of safety.
OP has done really well to have done that already.