Cannot add channels No "Channels" Section or "Install Channels Button"

[boomalator]

Server Version#: Version 1.14.1.5488
Player Version#: Version 3.77.4

https://support.plex.tv/articles/201053758-adding-removing-and-updating-a-channel/
Says:

1. Open Plex Web App
2. Choose Channels in the sidebar
3. Click ![Install Channels button]

I cannot see these items.
Checked Chrome and Edge on two computers, including the server.

[dane22]

Duplicate of How to add plugins?

Please don’t crosspost