unable to get Firebase documentID

ello, i'm running a query to Firebase and i need to get the document ID of the collection. This is the code to run the query:

Variable

private var ptListInCell = [PTList]()

@IBAction func getDataTapped(_ sender: Any) {
        SVProgressHUD.show()
        
        if HOSP != (hospnameTxt.text!) {
            ptListQuery = ptListCollectionRef?.whereField("hosp", isEqualTo: (hospnameTxt.text!))
        }
        
        ptListQuery?.getDocuments { (snapshot, error) in
            if let err = error {
                debugPrint("error getting data: \(err)")
            } else {
                guard let snap = snapshot else { return }
                for document in snap.documents {
                    let data = document.data()
                    let ptName = data[PTNAME] as? String ?? ""
                    let assignedMd = data[ASSIGNEDMD] as? String ?? ""
                    let officeMd = data[OFFICEMD] as? String ?? ""
                    let assignedDate = data[ASSIGNEDDATE] as? String ?? ""
                    let seeNoSee = data[SEENOSEE] as? String ?? ""
                    let room = data[ROOM] as? String ?? ""
                    let app = data[APP] as? String ?? ""
                    let documentId = document.documentID
                    print("documentId", documentId)
     
                    let newPtList = PTList(ptName: ptName, assignedMd: assignedMd, officeMd: officeMd, assignedDate: assignedDate, seeNoSee: seeNoSee, room: room, app: app, documentId: documentId)
                    print("newPtList", newPtList)
                    print("documentId", documentId)
                    
                    self.ptListInCell.append(newPtList)
                }
            }

it pulls everything but the documentID. When i print to the console:

print(ptlist?.documentId asAny)

Result is nil.

thank you!