[{"notifications":[{"author":"5862184743205863247","type":"friend","value":"5862184743205863247","avatar":"https://avatars.dicebear.com/api/avataaars/ZAZA.png","id":"5861675623319076687","createdAt":"2022-03-24T13:43:06.637Z","status":"Hello! I just joined unchat!","username":"ZAZA"}]}]

db.collection.aggregate([{$set:{notifications:{$map:{input:"$notifications",as:"n",in:{author:{avatar:"$$n.avatar",id:"$$n.id",createdAt:"$$n.createdAt",status:"$$n.status",username:"$$n.username"},type:"$$n.type",value:"$$n.value"}}}}}])