curl --request POST \
  --url https://api.hubapi.com/crm/v3/associations/{fromObjectType}/{toObjectType}/batch/create \
  --header 'Content-Type: application/json' \
  --header 'private-app: <api-key>' \
  --data '{
  "inputs": [
    {
      "from": {
        "id": "53628"
      },
      "to": {
        "id": "12726"
      },
      "type": "contact_to_company"
    }
  ]
}'

{
  "completedAt": "2023-11-07T05:31:56Z",
  "numErrors": 123,
  "requestedAt": "2023-11-07T05:31:56Z",
  "startedAt": "2023-11-07T05:31:56Z",
  "links": {},
  "results": [
    {
      "from": {
        "id": "53628"
      },
      "to": {
        "id": "12726"
      },
      "type": "contact_to_company"
    }
  ],
  "errors": [
    {
      "subCategory": {},
      "context": {},
      "links": {},
      "id": "<string>",
      "category": "<string>",
      "message": "<string>",
      "errors": [
        {
          "subCategory": "<string>",
          "code": "<string>",
          "in": "<string>",
          "context": "{missingScopes=[scope1, scope2]}",
          "message": "<string>"
        }
      ],
      "status": "<string>"
    }
  ],
  "status": "PENDING"
}