Open subscription checkout

Returns a browser handoff to the existing Benjiads checkout. The owner signs in and authorizes the recurring subscription; this call does not charge a card or grant access. Existing subscribers can manage billing there.

curl -X POST "https://example.com/billing/checkout" \  -H "Idempotency-Key: stringst"

{  "url": "http://example.com",  "action": "complete_in_browser"}