Make a hub the default one

Marks one of your own hubs as the default one and clears the flag on every other hub you own. A team uses one hub, the one a campaign created without a knowledgeHubId grounds on: the team owner's default when it is built or building, else the oldest built one among the members' defaults. A teammate's hub is readable through GET /business/knowledge-hubs/{hubId} but cannot be made your default and answers 403 KNOWLEDGE_HUB_OWNER_ONLY. The response echoes the request; read the hub back with GET /business/knowledge-hubs/{hubId} to confirm.

Errors:

• 403 KNOWLEDGE_HUB_OWNER_ONLY — The hub belongs to a teammate; you can read it, but only its owner can make it their default hub.
• 404 KNOWLEDGE_HUB_NOT_FOUND — No hub with that id, it was deleted, or it belongs to another team.
• 422 VALIDATION_FAILED — hubId missing or not a 24-character hex id.
• 429 RATE_LIMITED — More than 30 knowledge-hub/campaign requests in a minute (or 1000 in a day). Knowledge hubs share the campaigns bucket.

Requires one of the following token scopes: campaigns.