Would be good if you have it but for my practical test I showed the examiner my theory certificate and said we do not need to see that because you need a number on the theory certificate to book your practical test at the first place but different examiners might do it differently so best if you brought it with you.
They like you to bring it just in case, but it is all electronic these days so 99.9% of the time you will not be asked for it. Sometimes we have a marker which requests us to ask for it, but this is only when the computer screws up and thinks it might be expired or have been impersonated. I have not been asked to view one in half a dozen years.