add env vars section

Author: silentoplayz

docs/features/chat-features/chatshare.md

@@ -197,6 +197,18 @@ If an administrator revokes your permission to create public chats (either by ch
 
 This is a security measure to ensure that users who are no longer supposed to have public sharing capabilities do not have publicly accessible content.
 
+## Administrator Configuration
+
+Administrators of an Open WebUI instance can configure certain features and permissions using environment variables.
+
+### Environment Variables
+
+The following environment variables can be used to control the chat sharing functionality:
+
+-   `USER_PERMISSIONS_SHARING_PUBLIC_CHAT`: Set this to `true` to allow users to create public share links. If set to `false`, users will only be able to create private links that require authentication. This is equivalent to the "Enable Public Chat Sharing" permission in the admin panel.
+-   `USER_PERMISSIONS_CHAT_SHARE`: Set this to `false` to disable the chat sharing feature entirely. If disabled, users will not see the "Share" button in the chat interface.
+-   `ENABLE_COMMUNITY_SHARING`: Set this to `false` to disable the "Share to Open WebUI Community" feature. If disabled, the button will not be visible in the "Share Chat" modal.
+
 ## Automatic Revocation and Expiration
 
 Shared links can be automatically revoked under several conditions: