If you are both resident here I believe you can get “l’interdiction de sortie de l’enfant du territoire français sans l’autorisation de ses (2) parents”. Particularly if the children are french born.
And perhaps something you need to seek now before it’s an issue, as without any constraints there is currently nothing to stop either parent taking child /children out of the country. Information here
It will be a matter discussed and agreed as part of the divorce process, with the children’s needs given priority.
But you need to get professional advice asap if you are concerned about the children.