ok, here is my take at a guide. [this is my first attempt so please bear with me]
pre-requisites: accounts and access to IDE, Kasa and IFTTT
Step 1: create a simulated switch in IDE. log in to graph.api.smartthings.com > go to ‘my devices’ > new device > give it a name, network ID (it can be anything you like) > select ‘simulated switch’ under Type > select your location and other fields > click create
Step 2: give access to your smartthings and kasa in IFTTT quite straight forward. login to IFTTT and search for smartthings, and Kasa under services. both will require you to login to respective accounts and provide access to your devices.
Step 3: create applets in IFTTT go to my applets > new applet > If simulated switch turned on, then turn on your kasa plug.
Similarly create another applet with the rule that if simulated switch turned off then turn off your kasa plug.
That’s it! hope it helps.
regrettably, i couldn’t get down to doing it with screenshots.