Swift - SQLite3 Wal Checkpoint -> Unsafe Pointer Parameter

I have a program that adds data from CSV files to core data. Once I have saved the managed object context to the persistent store I want to run a checkpoint to flush the contents of the WAL file into the SQLite file. I have added code to my class in an attempt to do so but am unable to determine on the line "sqlite3_wal_checkpoint( ...)" what to put in the unsafe pointer <cchar> parameter (denoted with ??????? in the code).

class UpdateCoreData: ObservableObject {
    @Published var isLoading: Bool = true
    var moc: NSManagedObjectContext
    init(moc: NSManagedObjectContext) {
        self.moc = moc
        Task {
            await IsDataStoreEmpty(moc: self.moc)
            let fund1 = CSVtoCoreData(fundName: "Fund1", fileName: "Fund1.csv")
            let fund2 = CSVtoCoreData(fundName: "Fund2", fileName: "Fund2.csv")
            let fund3 = CSVtoCoreData(fundName: "Fund3", fileName: "Fund3.csv")
            await fund1.CSVtoCoreDataG(moc: self.moc)
            await fund2.CSVtoCoreDataG(moc: self.moc)
            await fund3.CSVtoCoreDataG(moc: self.moc)
            do {
                try moc.save()
            } catch {
                print("Error saving. \(error)")
            }
--- start of added code
            let fileURL = URL(fileURLWithPath: "/Users/Chris/Downloads/Persistent Store 2/Funds.sqlite")
            var dataBase: OpaquePointer?
            sqlite3_open(fileURL.path, &dataBase )
            if sqlite3_open(fileURL.path, &dataBase) != SQLITE_OK {
                print("Unable to open sqlite file")
            } else {
                print("Succesfully opened sqlite file")
            }
            sqlite3_wal_checkpoint(dataBase, ??????? )
            sqlite3_close(dataBase)
--- end of added code
            DispatchQueue.main.async {
                self.isLoading = false
            }
        }
    } // end init
}