Export the campaign's leads to CSV

Exports every lead in the campaign as a CSV document returned inline in the JSON body under csv (first row is the header). There are no filters - use GET /business/campaigns/{campaignId}/leads when you want a page or a search. Very large campaigns are refused with 422 EXPORT_LIMIT_EXCEEDED rather than truncated. Only the token owner's own campaigns can be exported: a campaign delegated to you, one shared by your team's visibility settings, and a deleted one all answer 404. Rate limit: this endpoint has a tighter cap of 3 requests/minute and 30/day, applied inside the shared campaigns bucket of 30 requests/minute and 1,000/day per token owner (shared by every campaign, scheduled-send, campaign-template and knowledge-hub endpoint).

Errors:

• 404 CAMPAIGN_NOT_FOUND — No campaign with this id exists, it belongs to another account (including a campaign delegated to you or shared by your team's visibility settings), or it has been deleted.
• 422 NO_LEADS_TO_EXPORT — The campaign exists but has no enrolled leads to export yet.
• 422 EXPORT_LIMIT_EXCEEDED — The campaign has more leads than a single export may contain.
• 422 VALIDATION_FAILED — campaignId is not a 24-character hex id.
• 429 RATE_LIMITED — Either this endpoint's own cap (3 requests/minute, 30/day) or the shared campaigns bucket (30/minute, 1,000/day for this token owner, shared by every /business/campaigns, /business/scheduled-sends, /business/campaign-templates and /business/knowledge-hubs call) was exceeded. The RateLimit-* headers on the response describe the shared bucket, so a refusal from this endpoint's own cap can still report requests remaining and carries no Retry-After.
• 500 UNEXPECTED_ERROR — An unhandled failure; the detail stays in our logs and is never returned.

Requires one of the following token scopes: campaigns.