[Tkinter] Notebook accessing a specific tab using a button from a toplevel frame

[honestie]

Sorry, really new to all this.

Error:
Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\AppData\Local\Programs\Python\Python37-32\lib\tkinter\__init__.py", line 1702, in __call__
    return self.func(*args)
  File "C:\PycharmProjects/scrollbar/.idea/scrollbar.py", line 83, in result1
    ttk.Notebook.select(self.tab7)
  File "C:\AppData\Local\Programs\Python\Python37-32\lib\tkinter\ttk.py", line 892, in select
    return self.tk.call(self._w, "select", tab_id)
_tkinter.TclError: bad command "select": must be configure, cget, instate, state, or identify