The 
Requester is the block that lets you place a standing order for an item so your Refined Storage network keeps a target amount in stock without you babysitting the crafting grid.
Placing and Connecting the Requester
Place the Requester against your network (or connect it with a cable) so it joins the Refined Storage network. Open its interface. You will see a slot for the item you want to track and fields for the quantity you want kept available. Put the item you want automated into the slot — you can pull it straight from your system's search if you have JEI/REI integration.
Configuring the Order
Set the amount you want the network to maintain. The Requester compares what is currently stored against your target and, when stock drops below it, emits a crafting request for the difference. This is the key behavior: it does not craft the full amount every time, only enough to top the stock back up to your target. Confirm the request is registered, then watch your Crafting Monitor or crafting grid to see the job appear.
Verifying It Works
Craft or consume some of the tracked item, then check that a new crafting job is scheduled automatically. If nothing happens, make sure the Requester is actually on the network, that a valid pattern exists for the item, and that your crafters have the ingredients available.