Hello, you can only operate the Hue Outdoor Lightstrip with a power supply unit. You can cut off the plug on the power supply unit and connect it directly to the power terminals in a flush-mounted box, for example.

The lamp works with 24V, the power supply is mandatory, but as others write here, you can connect the power supply directly to the 230V mains without a plug.

This is difficult without a black box (transformer). Abee up to the transformer can be shortened on the 230V side and reconnected.