const options = {
method: 'POST',
headers: {'Content-Type': 'application/json'},
body: JSON.stringify({contact_ids: ['3c90c3cc-0d44-4b50-8888-8dd25736052a']})
};
fetch('https://api.example.com/api/v1/contacts/bulk-delete', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));