Hi philvip,
I'm sorry for this inconvenience. Please follow these steps to make the extension work:
1. As an extension is just a WordPress plugin, you need to install it like a normal WordPress plugin by going to Plugins, click "Add new", then click "Upload plugin".
2. Choose the .zip file you downloaded from the download link in your email and click "Install now"
3. After finish upload, click Activate.
That's all for installation.
To create tabs for meta boxes (make sure you know how to register meta box and define fields), please follow this documentation (I'll update this docs to cover the installation step above).
If you need any help, please let me know.
Thank you.
.
