Add subscriber to form (by ID)
documentedAdd an existing subscriber to a form by their ID.
POST /v4/forms/{form_id}/subscribers/{subscriber_id}Formsno implementation yet0 runsInput
form_id*
Form ID
123
subscriber_id*
Subscriber ID
456
referrer*
Subscriber Referrer URL
https://example.com/landing
Calls Kit as you (your API key is your account); keychains.dev holds the credentials.