This is possible you use customer entities for the members, create a custom entity field call it Pin, input their pin there for each customer.
The last part of automation can be done a few ways. You can modify settle rule and remove the Display Payment Screen action, create an execute Automation Command Action
Insert that action into the Settle Rule:
For cmd Value enter the following code:
[?Enter Your Pin Number;;;OCN;]
Then save the rule and create an Automation Command Executed rule:
Insert your Display Payment Screen action;
Use the custom constraints shown in the screenshot.