In order to create an API key and password, you'll need to create a private app on your store. You can do this in the Apps section of the Shopify admin. At the bottom of that page is a link of "Manage private apps". You'll want to create an app for BaseLinker and give it the correct access scopes. The API key and password will autogenerate and can be found at the top of the app page. Please take care to share the key and password with them securely, and to not share it with any other parties. If in future you integrate with another service, you'll want to create a separate app with distinct credentials to share with them. Hope this is helpful!