Question on Ring Pro 2 doorbell installation

I plan to get an electrician to install this but before I do that I'd like to understand what is involved to make sure there are no problems.Looking at my existing doorbell chime, it looks like there is already a transformer in there:[https://i.imgur.com/lRtZQFt.jpg](https://i.imgur.com/lRtZQFt.jpg)Does this mean that the din rail transformer that comes with the Ring pro 2 will need to be installed in the existing chime box rather than the consumer unit?If so then can I just replace the existing chime box completely with this:[https://en-uk.ring.com/collections/accessories/products/enclosure-din-rail-transformer](https://en-uk.ring.com/collections/accessories/products/enclosure-din-rail-transformer)Thanks.