Create LinkedIn Campaign Group

Creates a LinkedIn campaign group — a 'Campaign' in the Campaign Manager UI. status: DRAFT | ACTIVE. If total_budget>0 is given, a total budget is assigned in the account's currency. RUN SCHEDULE: start_date / end_date ('YYYY-MM-DD'; end date runs to the end of that day, UTC). Empty start = now. With a total budget and no end_date LinkedIn's 90-day default end applies, so the budget is paced over 90 days — give end_date for event or short campaigns. objective_type set at GROUP level constrains EVERY ad set inside it: a group created with ENGAGEMENT can never host a Lead Generation or Website Visit ad set, and LinkedIn normally refuses to change it afterwards. Empty leaves the group open to every objective. Empty is the default and keeps the group open to every objective — set the objective on the individual campaign instead.

objective_type (LinkedIn's enum is SINGULAR — live-verified): WEBSITE_CONVERSION | WEBSITE_VISIT | WEBSITE_TRAFFIC | LEAD_GENERATION | BRAND_AWARENESS | ENGAGEMENT | VIDEO_VIEW | JOB_APPLICANT | CONVERSATION_STARTER | TALENT_LEAD | CREATIVE_ENGAGEMENT. Plural spellings (WEBSITE_CONVERSIONS / VIDEO_VIEWS / JOB_APPLICANTS) are auto-corrected. Objective CANNOT be changed after creation. If confirm=false, only a preview is returned; to apply, use confirm=true.