Connect Notion with an internal integration token

Notion internal integration token (ntn_… or secret_…)

Ingestion store name. A store that already exists is shared: every data source connected to it ingests into it, except another installation of the same account, which would ingest every item again. Without it, the account's default store, numbered past a store another installation of the account feeds. Rejected with 422 when the connect refreshes an existing installation and names a store other than its own.

Ingest into a store created for this connection: the connect fails with 409 when store_name names a store that already exists, and without store_name the default name is numbered past existing stores. Rejected with 422 when the connect refreshes an existing installation, which keeps its store.