Navigate to HACS in the menu of your Home Assistant
Use the top right 3 dots icon to add a custom repository.
Enter the URL of the repository in the Repository field and select Integration as a type, then click on Add.
Close the modal an look for the integration, by searching for Eaton Battery Storage System, click on the result and finally click on Download located on the bottom right corner of your browser.
Congratulations, you should now have access to your Eaton xStorage Home metrics in Home Assistant