Custom Wedding Ring Wasn’t Hallmarked

We bought my wedding ring in 2022 in a Hatton Garden Jewellers. It’s a Platinum band with 7 small diamonds.

I never noticed before but it wasn’t hallmarked. I’m aware it’s been 4 years since I bought it so do I have any rights when it comes to the Jewellers? Should I email or go in person to them? I just want it hallmarked.