Add products to my supply chain simulation and some problems

Question

I would like to add products to my supply chain simulation (Manufacturer, Wholesaler, and Retailers) To explain more: I created now a simulation of Manufacturer, 2 wholesalers and 10 retailers and I would like to create

• a population of client that orders from retailers by Poisson distribution (I don't know how to do it)
• if the retailer received the order he will check on current stock, if the order available he will fulfil the retailer, if not he'll send an order to the manufacturer.
• the manufacturer has full capacity.

Does anyone tell me how to create this ? I just made the simulation of moving truck from manufacturer to the wholesalers but without any order. I know about the tutorial on Anylogic and I'm applying it, but it's not what I'm thinking about I would like the demand from clients by Poisson distribution