How to alert/notify a user when a certain action (example uploading a particular doc on an Issue) is pending for more than 3 days?

Our business users are using Issues and Issue status within workfront to capture ,communicate and interact on a certain process with their agency stakeholders. There is a requirement wherein when the issue is assigned to the agency user, they have to upload a document. If the agency user has not uploaded the doc (issue has been awaiting for them to upload the document) for more than 3 days, then workfront should notify the business user. What is the best way to config this within workfront with or without workfront fusion?