Firebase Realtime Database から配列のvalueを取得するには

次のJSONツリーの配列の値を取得したいです(写真のfuda1L等)。私はsnapshotを引数にとってUserInfoClassという名のClassでその配列を[String]で取得しようとしましたが、オプショナルnilが出てきてしまいました。解決法をご教示頂きたいです。

Swift
1    func retriveData(){
2        
3        refUserInfo = Database.database().reference().child("users")
4        refUserInfo.observe(.value) { (snapshot)  in
5            let info = UserInfoClass.init(snapshot: snapshot)
6            //userInfo is [UserInfoClass]
7            self.userInfo.append(info!)
8            self.InfoTableView.reloadData()
9            
10        }
11    }

以下が 'UserInfoClass'です。

 init? (snapshot: DataSnapshot) {
        guard let applyDict = snapshot.childSnapshot(forPath: "ApplyInfo").value as? [String: Any] else {return nil }
        guard let peopleNum = applyDict["peopleNum"] as? Int else { return nil }
        print("peopleNum: (peopleNum)\n")
       
        guard let payType = applyDict["payType"] as? [String] else { return nil }
        print("payType:(payType)\n")
        guard let receiveType = applyDict["receiveType"] as? [String] else { return nil }
        print("receiveType: (receiveType)\n")
        guard let furigana2 = applyDict["furigana2"] as? [String] else { return nil }
        print("furigana2: (furigana2)")
        guard let prayman2 = applyDict["prayman2"] as? [String] else { return nil }
        print("prayman2: (prayman2)\n")
        guard let furigana1 = applyDict["furigana1"] as? [String] else { return nil }
        print("furigana1:(furigana1)\n")
        guard let prayman1 = applyDict["prayman1"] as? [String] else { return nil }
        print("prayman1:(prayman1)\n")
        guard let prayType2 = applyDict["prayType2"] as? [String] else { return nil }
        print("prayType2:(prayType2)\n")
        guard let prayType1 = applyDict["prayType1"] as? [String] else { return nil }
        print("prayType1:(prayType1)")
        guard let moneySum = applyDict["moneySum"] as? [Int] else { return nil }
        print("moneySum:(moneySum)\n")
        
        guard let fuda1Small = applyDict["fuda1S"] as? [String] else {return nil}
        guard let fuda1Mid = applyDict["fuda1M"] as? [String] else {return nil}
        guard let fuda1Large = applyDict["fuda1L"] as? [String] else {return nil}
        guard let fuda3Small = applyDict["fuda3S"] as? [String] else {return nil}
        guard let fuda3Mid = applyDict["fuda3M"] as? [String] else {return nil}
        guard let fuda3Large = applyDict["fuda3L"] as? [String] else {return nil}
        guard let fuda5Small = applyDict["fuda5S"] as? [String] else {return nil}
        guard let fuda5Mid = applyDict["fuda5M"] as? [String] else {return nil}
        guard let fuda5Large = applyDict["fuda5L"] as? [String] else {return nil}