You may need to reset it. Hold in the little button as you plug it in/switch it on. The blue light should blink slowly showing its ready for inclusion, then you’ll be good to go.
press and hold the button while plugged in until the LED starts blinking.
press the button 5 times fairly quick. sometimes 7 or 10 times are sequences that work to reset a device. this is not a sure thing, but you’d be surprised what’s not documented.
Instead of selecting a model when trying to join, select the option Scan Nearby.
It seems I can’t get it into this pairing mode. I’m sure this is an official SmartThings power outlet as well, or Samsung one but doesn’t have any branding on which is strange. I can’t remember if I got it in the starter kit years ago or not.
This is it…. It has a button on either side, I’ve tried both together. Each side etc
It sounds like when you hold one of the buttons in when powering it up, the LED turns on. That IS the reset indication for a Centralite Series 3 plug which looks remarkably like yours, and Centralite did make plugs for SmartThings. Have you tried pairing it from that state, or did the lack of blinking deter you?
You can just use ‘Scan Nearby’ in the app. Choosing specific devices is more elegant, but is pretty much equivalent in many cases. As long as you aren’t being prompted for specific information it often doesn’t actually matter which device you choose.
Having the same issue, anyone got any suggestions? Tried what the OP did which is holding down the button whilst plugging in but light just goes blue then goes out. These outlets seem to be garbage tbh.