The receiving team takes the referral. Only a pending referral can be accepted.

Accepting creates a new contact on your team from personSnapshot, assigned to
the API key's user, and returns its id as receivedPersonId. Shared notes are
copied unless skipNotes is true. Shared custom fields are copied (and created on
your team if missing) unless you narrow them with customFieldIds.

The sending team gets a referralsAccepted webhook.