SAP Purchase requisition APP - scale pricing not showing when create pr (MM-FIO-PUR-REQ-SSP)

Hello Gourou's

I would similar to usage terms scales erstwhile available, astatine pr creation 

Unfortunately nary information is showing erstwhile one click connected the hyperlink:

In the PIR one bash person scaleprices set

My json record besides contains data, but present i'm not definite astatine each what each parameter should incorporate arsenic value? 

"PRICE_SCALES": [{"SCALETYPE": "01", "LOW": "3","HIGH": "5", "PRICE": "20"{*}}]}]

what represents Scaletype; Low and High?

Did one miss a required setup successful the system?

Does anyone person a step-by-step config guide?

Thanks a batch for your benignant help