You do not need an in-home display to take part.
As long as you have a connected smart meter and half-hourly readings enabled you can take part. We will need to verify your address matches the address linked to your smart meter but you can do that without your IHD.
Please note: Your in-home display (IHD) is different to your smart meter. Your IHD is the little screen that sits on a shelf in your house and displays your energy usage info.