The block of sideload add-in on Office 2013

I am developing an office add-in, it work fine on Office 2016 and later.

Now I wanna test it on Office 2013, sideload it by this article strictly: 

https://docs.microsoft.com/en-US/office/dev/add-ins/testing/create-a-network-shared-folder-catalog-for-task-pane-and-content-add-ins

But it get nothing:

I tried Windows 7 and Windows 10 and get same result. Can anyone point me a direction?