const options = {
method: 'POST',
headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
body: JSON.stringify({code: '<string>', customer_id: '<string>'})
};
fetch('https://api.useautumn.com/v1/referrals/redeem', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));