# channel_not_found when posting to DM or private group with Slack Bolt
Calling `app.client.chat.postMessage` in a Bolt app with the channel ID of a direct message or private group returns `channel_not_found`, while posting to public channels the bot was invited to works fine. The bot user OAuth token is used. The same call pattern succeeds for public channels, so the token itself is valid.
## How to handle it
`channel_not_found` here means the bot user is not a member of that conversation. A bot can only `chat.postMessage` to DMs and private groups it has been added to. Fix: invite the bot user to the DM/private group (or have a user start a DM with the bot), then the same `chat.postMessage` call succeeds. If you need to reply from a slash command, prefer `respond()` over `say()`/`chat.postMessage` in the listener, which posts back into the originating conversation without needing membership.
Source: https://github.com/slackapi/bolt-js/issues/365