You will need to clear the codes before a regen can happen. I think some garages can force it for some cash.
Question is why hasn't it regen, unless its high mileage or low mileage short journeys car. What temps does it achieve?
I replaced both my stats as mine would struggle to achieve 76c in the cold with heaters on. The stats had failed and the new ones sit at 92c every journey within about 10mins.
If yours doesn't achieve at least 78c it will never regen and get clogged.