[greengrass] how to add environment variable

Hi. You can't do an export like that. Here is a JSON recipe example for Setenv: https://github.com/awslabs/aws-greengrass-labs-kvs-stream-uploader/blob/main/recipes/aws.greengrass.labs.kvs.stream.uploader-sample.json#L27

And a YAML example: https://github.com/awslabs/aws-greengrass-labs-jupyterlab/blob/main/recipes/aws.greengrass.labs.jupyterlab.yaml#L30

is there any type of use greengrass deploy kvs to device?

If I understand your question correctly, this component is likely of interest. It builds the KVS C SDK, links it into the component, and publishes the component for deployment: https://github.com/awslabs/aws-greengrass-labs-webrtc

I think you need to add RequiresPrivilege: true, and this works for me

  Run:
    RequiresPrivilege: true
    Script: "<command>"
    Setenv:
       LD_LIBRARY_PATH": "{artifacts:path}/lib