const options = {method: 'POST'};

fetch('http://localhost:8000/api/v1/invitations/{token}/accept', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "success": true,
  "data": {
    "organizationId": "<string>",
    "member": {
      "userId": "<string>",
      "organizationId": "<string>"
    },
    "invitation": {
      "id": "<string>",
      "status": "<string>"
    },
    "organization": {
      "id": "<string>",
      "name": "<string>",
      "slug": "<string>"
    }
  },
  "meta": {
    "requestId": "<string>",
    "timestamp": "<string>"
  }
}