postman-vars-to-insomnia.js

const postmanEnv = {
	"id": "7a40704a-d4e2-4948-ba35-826a93f2bf0f",
	"name": "local",
	"values": [
		// values would go here
	],
	"_postman_variable_scope": "environment",
	"_postman_exported_at": "2019-04-23T18:36:01.716Z",
	"_postman_exported_using": "Postman/7.0.9"
};

const env = postmanEnv.values.reduce((acc, {key, value}) => {
    if(acc.value) {
      return { [key]: value };
    }
    return { ...acc, [key]: value }
});

console.log(JSON.stringify(env));