Server-side, singleplayer working Fabric utility mod for Minecraft 26.1.2+. Open Ender Chests with /enderchest and manage access through an operator whitelist GUI.
An image of how the command will look like in the chat
Includes toggling enable/disable whitelist, add/remove player to whitelist, and whitelisted players, and the players' ender chests.
How the /enderchest command gui looks like