[kabouseng]

You can either wire a relay yourself, your smart plug just switches the relay, and you can size the relay according to your needs.

Or use smart switches made for geysers. Something like the sonoff pow3 can handle up to 5.5kW. Since it is just a relay inside I am pretty sure it can handle inductive loads fine.

https://sonoff.tech/product/diy-smart-switches/powr3/