If your pharmacy is closed, you will need to transfer your prescription to another pharmacy. Online tools like RxOpen track which pharmacies remain open during emergencies.
If your pharmacy is a chain, contact another location, and they should be able to access your records and refill your medication. Or your new pharmacy may be able to contact Express Scripts for your medication information if you have a valid prescription on file.
You can also contact your doctor and ask them to send your prescriptions to a new pharmacy.