It's two steps, not one
Step one: Dashboard → Integrations, connect the account. This stores the credential, encrypted.
Step two: Dashboard → your campaign → Apps, wire that account to the campaign and choose when it fires — on entry, on win, or on reward claim.
Both steps are required. A connected account with no campaign wired to it does nothing at all.
Which providers actually deliver
Thirteen have a working outbound endpoint today: Mailchimp, Klaviyo, ActiveCampaign, Brevo, Kit, MailerLite, SendGrid, Campaign Monitor, HubSpot, Shopify, Customer.io, Zapier, and plain webhooks.
The other 66 in the directory store credentials and are ready for an endpoint to be filled in. The Apps page tells you which is which when you pick one, so you're not left wondering why nothing arrived.
When it goes wrong
Every delivery attempt is logged. The Apps page shows the last 20 with their status codes and error messages. A failed push never blocks an entry — someone entering your giveaway should not care that your Mailchimp key expired.
If a provider returns 401 or 403 the connection is marked as needing reauthentication, so you can spot it before the campaign ends.
Consent
If you're building a mailing list from a giveaway, turn on the notification opt-in in the campaign's Settings tab. It adds a checkbox to the entry form and stores the answer against the entrant, so you can filter your export to people who actually agreed.