We are trying to roll out a better way employees can enter in Requisition instead of using excel and emailing them. We enabled Purchase Requisitions and would like to instruct employees to use generic codes like "Materials & Supplies" or "Office Supplies" since most of the time they are ordering something special for a job. However when they select materials & supplies as the item they aren't given the option to select a vendor. It is blank. We need to be able to allow them to select any vendor they want from our vendor list. Any ideas?

I attached an example screenshot that shows the vendor list as being blank.