In the Hub, you're shown your Next Issue Date:

The next issue date is when we expect your next prescription to be delivered by. Depending on your prescription type, this will have been sent out 2-4 weeks before the date shown.
Resend Prescription
We’ve made it easy to request a resend right from your Hub account.
You can only request a resend once every four months, so make sure everything's correct before confirming.
To resend:
Log into the Hub
Click My Medication (you’ll find it at the bottom centre of the screen)
Click Resend Medication

Choose a reason from the dropdown
Double-check your prescription preference is correct
If you select Other, just put your reason into the text box.
Click Continue – and that’s it! Your request will be on its way.
If you're still having problems, please get in touch with us via the chatbot in the bottom right of the screen.