[Tkinter] Python 3 change label text

[gw1500se]

I have a tkinter label that I want to change. I've found several articles on how to so that but none work. If I try to use 'textvariable' I get an error that 'text' is required. If I set 'text' to '' then it does not change when I set the variable.

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      self.var1=StringVar(self.root)
      self.var2=StringVar(self.root)
      self.line1=CL.CustomFont_Label(self.root,textvariable=self.var1,
font_path=fontPath,size=36).grid(row=0,column=0,columnspan=5)
      self.line2=CL.CustomFont_Label(self.root,textvariable=self.var2,
font_path=fontPath,size=36).grid(row=1,column=0,columnspan=5)
      self.var1.set(self.pad('Stoker II'))
      self.var2.set(self.pad('Initializing'))
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      self.root.mainloop()

Can someone give me the right syntax for changing label text? TIA.