Controlling non-fitting led lights

What you can use is a “controller”.

12 volt DC power supply to the controller, the LED strips connected and wireless connection via Zigbee or Z-Wave to your SmartThings hub.

Depending on your kind of LED strips you have white (even cool and warm white), RGB, RGBW & RGBWW (aka RGB-CCT).

Here an example: Gledopto Zigbee RGB controller

Some pictures of a controller:

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Schematics:

1639172954-1639525677