curl --request POST \
  --url https://app.untetherlabs.com/api/v1/authorization/roles/{roleId}/users \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "userIds": [
    "3c90c3cc-0d44-4b50-8888-8dd25736052a"
  ]
}
'

{
  "assigned": 123
}