@allister Ok, finally I got your point. You define function as actions in Main function. _call(_on_start, null)! is placed only after functions defined through main interface.
So in order to make it work, you need to create BucketOne and BucketTwo function through main interface and place code inside it with "Execute code" action, like this https://drive.google.com/uc?id=1pIAaHwmEDpz5D3Iiw8MWyRvmPGlYm5-R&export=download