Send the commenter an Instagram DM about their comment. Reaches a real person. Instagram allows one private reply per comment, only within 7 days of the comment, text only (≤ 1000 characters) — it cannot be edited or resent, and Instagram appends a link to the post. The DM is persisted in the commenter's Instagram chat (dmChatId), where the normal 24-hour messaging window opens only once they reply.

Not available for the account's own comments (400), deleted comments (409), comments older than 7 days (409 IG_PRIVATE_REPLY_WINDOW) or comments that already received a private reply (409).

Security:

• The organisationId in the URL must match the organisation your JWT was issued for — requests for a different organisation fail with 401.
• Requires CRM_ADMIN, ACCOUNT_OWNER, or CRM_BOT role; other roles receive 403.
• Comments are only available on INSTAGRAM (Instagram Login) channels that were reconnected with the comments permission; a workspace without comments enabled receives 503 INSTAGRAM_COMMENTS_NOT_MIGRATED.