const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({email: 'jsmith@example.com', role_ids: [], send_email: true})
};

fetch('https://api.keystoneos.xyz/v1/platforms/{platform_id}/invitations', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "id": "<string>",
  "invitee_email": "<string>",
  "inviter_name": "<string>",
  "roles": [
    "<string>"
  ],
  "created_at": "<string>",
  "expires_at": "<string>",
  "invitation_url": "<string>"
}