using (SQLiteCommand getBooklet = new SQLiteCommand($"SELECT "rowid", File_Name FROM Booklets WHERE Id = {int.Parse(key)}", dbConnection))

using (SQLiteDataReader currentCustomerReader = getBooklet.ExecuteReader(System.Data.CommandBehavior.KeyInfo & System.Data.CommandBehavior.SequentialAccess))

currentCustomerPdf = currentCustomerReader.GetBlob(1, true);

System.InvalidOperationException: No RowId is available
    at System.Data.SQLite.SQLiteBlob.Create(SQLiteDataReader dataReader, Int32 i, Boolean readOnly)
    at System.Data.SQLite.SQLiteDataReader.GetBlob(Int32 i, Boolean readOnly)
...