Hey, so the pots on Pepper will either act as an attenuator to the CV signal you have plugged into one of the input jacks on the left hand side, or if nothing is plugged in then the pots are connected directly to the analog inputs on Bela.
This means that if you want to read from them with nothing connected you use the [adc~ 3 4 5 6 7 8 9 10]. This will give you the signal that varies between 0.0 and 1.0 for each pot. Note that the signal is at audio rate, like all the analog signals on Bela so ~ should be used throughout.
Do you have the first revision of Pepper? The two extra buttons were added for rev2 so that might be the case.
There is no need to add an extra signal to the scope abstraction. You can just connect any audio rate signal to the inputs and you will see it one the scope once launched in the browser. If you want to connect a control rate signal you will need to first convert it with [sig~].
A good test will be to connect [osc~ 20] to one of the inputs of the scope and to check if that is pulling through.