Help please? Smart switch to replace Myson Remote Switch for plinth heater

Dipping my toe into HA and in our kitchen we have a Myson Kickspace 500 plinth heater, which is controlled by a Myson Remote Switch at the wall.
Controls on this switch are Fan On/Off and Fan speed low/high…
I’m struggling to find anything like-for-like to replace the Myson switch with and hoping someone has experience of this scenario!
I’m UK based btw
Attached is a pic of the inside of the switch with current wiring, and the manufacturers guide for this switch is here at the bottom of the page under “Metallic Remote Switch”
https://blobfilesprod.purmogroup.app/public/306789/154921

Thanks!
Sam