Where in that LoC does it even mention “driver”? Stop putting yourself into self induced panic.
Even if it did mention “driver”, how do they know who the driver is unless you, as the Keeper, blabbed it to them?
They have given you, the defendant (not the “driver”) 30 days to pay. So what?
I can tell you with greater than 99.9% certainty that this will never reach a hearing and will, in due course be discontinued, if not struck out first, as long as you follow the advice.
You can either respond to their response or just ignore it and wait for the claim to follow. If you want to respond, just do a search of the forum form other recent similar cases and use one of those for your own.
When you receive the claim, come back and show us the a particulars of Claim (PoC) and the issue date of the claim. Again, just do a search for any other recent DCB Legal issued claims to know what is involved.
No one pays a penny for any defended DCB Legal issued claims to if you follow the advice given here.