Add Event Admin

curl --request POST \
  --url https://api.roostedhr.com/api/1_12/events/{id}/admins \
  --header 'Content-Type: application/json' \
  --header 'X-API-KEY: <api-key>' \
  --data '
{
  "personnel_id": 123
}
'

{
  "error": "<string>"
}