Codex app
The desktop app, the IDE extension, and Codex CLI share MCP settings on the same computer, in ~/.codex/config.toml. Set Flovia up on the Codex CLI page. Keep your key out of the chat.
If you open the app from outside the terminal, it does not see that terminal’s environment. Put FLOVIA_KEY where the app can read it, then quit the app and open it again. A saved variable name does not set the value.
To remove the shared setup, use the removal command on the CLI page.