In Postman, create an environment with your Escher details:
escher-credentialScope: ingatlancom
escher-accessKeyId: moderation_icom_v1
escher-apiSecret: abcd1234
Copy the contents of the postman-pre-request.js file to the Pre-request Script tab.
Add the following headers to the request:
X-Escher-Auth: {{auth}}
X-Escher-Date: {{date}}
npm install
npm install -g browserify
browserify node-postman.js > postman-pre-request.js
You can test the endpoint with client.js using node.
Sometimes you have to play with Postman Interceptor settings.