The features within are only available to Slack workspaces on an Enterprise plan.
Don't have a paid plan? Join the Developer Program and provision a fully-featured sandbox for free.
Usage info
Response
You may also receive a "partial" success response when some of the provided channels in the channel_ids are removed successfully. In this case, invalid_channels contains the channels that could not be removed.
{
"ok": false,
"error": "channel_not_found",
"invalid_channels": ["C1234D1R4", "C1234D1R5"]
}
You might see a partial success if you do not have enough permissions to manage all the specified channels, or if some channel_ids are not valid, or if the types of some channels are not supported.