If there are no actionable instructions for you in the parcel tracking details, the shipment may get delivered without needing further action from you, so our suggestion is to wait for further guidance from Customs unless the delay continues for another 3 days.
Alternatively, you could contact FedEx at 18007432626 (press 2 and 0 to speak to customer service officer) with your tracking number to see if they have any information on the shipment - some times they already have guidance on it but the information is still making its way to shippers through the communication network. If they ask for some paperwork and you require support, you may reach out to us and we will see how we can help!