How to use Custom Node input "samplerCUBE" variable in Material

Hi All,

I want to using a custom node to create a transparent refraction effect in the material, in order to use the cube texture, but when I write code need to input a “samplerCUBE” variables, I try to use “textureSamplerParameterCube” node, but there is an error(in picture), could you tell me what should I use way to input, thanks!