There is a difference between the Custom tkinter progress bar, and the regular tkinter one. In the video above, I describe on of the different ways of how to indirectly define the minimum, maximum, and progress value of this CTkProgressBar. The most important things are:

associating the widget with a IntVar()

Set the initial value to 0

Define the step value that is equal to 1/[number of steps]

Define the actual value that is also equal to 0

After each progression (step), increase the actual value with the step value.