Darn. Honestly, TP-Link is kind of a mess right now. They’ve got the original Kasa and Tapo lines (they bought Tapo), which were completely separate until recently. Now the Tapo app can apparently control Kasas, but then you can never go back to using the Kasa app. But they’ve also clearly stated that they aren’t retiring Kasa.
EDIT: I’ve since learned that Kasa devices can still work in the Kasa app after being ported to Tapo.
There are Kasa plugs that use Matter, and your EP25 that apparently needs Bluetooth for setup, and appears to prioritize HomeKit. And I guess neither will work with the Kasa binding. Sheesh.
If you have HomeKit, maybe you can use that to attach it to openHAB in a roundabout way. If it’s still returnable, I would personally just do that instead.