im having an error stating "The method '[]' can't be unconditionally invoked because the receiver can be 'null'.
Try making the call conditional (using '?.') or adding a null check to the target ('!')." Ive tried to add the '!' mark as stated and searching online but it doesn't resolve the issue. any ideas?

```
factory UserModel.fromSnapshot(DocumentSnapshot snapshot) {
    return UserModel(
      name: snapshot.data()["name"],
      email: snapshot.data()['email'],
      phoneNumber: snapshot.data()['phoneNumber'],
      uid: snapshot.data()['uid'],
      isOnline: snapshot.data()['isOnline'],
      profileUrl: snapshot.data()['profileUrl'],
      status: snapshot.data()['status'],
      designation: snapshot.data()['designation'],
      company: snapshot.data()['company'],
    );
  }

```