Mendix integration with SignEasy. SignEasy is a digital signature service similar to Docusign and Hellosign, but cheaper.
You need to create an account on SignEasy, and set the API key (access token) + clientID in the Config entity.
Callbacks won't work locally, so default callback url is https://signeasy.requestcatcher.com/, so you'll be able to see the API callbacks sent by SignEasy, and send the payloads using Postman to your local instance.
You can find the documentation here