*** The SharePoint Page Guide add-in works in conjunction with another add-in i.e. SharePoint Page Guide Web Part, which is only available from the SharePoint Page Guide Web Site. This requires installation on your environment outside of the Microsoft Office Store processes due the level of required permissions. A tenant administrator will need to deploy this specific add-in to the tenant app catalog site manually, so that it can be installed to your environment. We have added required step needs to be follow to install the another add-ins with the add-ins package you downloaded from the SharePoint Page Guide Web site. When apps are installed outside of the Microsoft Office Store, they may bypass any, and all, safety and security checks provided by Microsoft.
If you have not done so already, it is recommended that you establish contact with the SharePoint Page Guide Support before proceeding with installation. Consider trying this add-in on a separate SharePoint Tenancy before installing it on your primary SharePoint site(s).
Downlaod the package from the above link and unzip it. Package contains below listed two files: