post https://api.apollo.io/api/v1/emailer_campaigns//add_contact_ids
Use the Add Contacts to a Sequence endpoint to add contacts to the existing sequences in your team's Apollo account.
In Apollo terminology, a contact is a person that your team has explicitly added to your database. Only contacts can be added to sequences. To enrich a person's data so that they become a contact, call the People Enrichment endpoint.
This endpoint requires a master API key. If you attempt to call the endpoint without a master key, you will receive a 403 response. Refer to Create API Keys to learn how to create a master API key.