Install as per standard Magento 2 extension, and you will find the configuration settings under Admin Panel > Stores > Collect i Store. Each of the configuration options are self-explanatory.
This step is recommended as it enables you and your customers to use the Google Maps location search functionality of Collect in Store, allowing your customers to easily locate their nearest collection point. Click the following link to get a FREE API key, ensuring you enable "Google Places API Web Service" and "Google Maps JavaScript API" in the relevant Google administration areas: https://console.developers.google.com/apis?pli=1
Note down your Google API Key and add it to the Absolute Collect in Store configuration, it will look something like this example: AIzaSyG3OoDgQj5f36sXpsAdHyQasHDgAs4IrjU