curl --request GET \
  --url https://app.fliqr.ai/api/users/{user_id} \
  --header 'X-ACCESS-TOKEN: <api-key>'

{
  "id": 123,
  "page_id": 123,
  "first_name": "<string>",
  "last_name": "<string>",
  "channel": 123,
  "profile_pic": "<string>",
  "locale": "<string>",
  "gender": 123,
  "timezone": 123,
  "last_sent": 123,
  "last_delivered": 123,
  "last_seen": 123,
  "last_interaction": 123,
  "subscribed_date": "<string>",
  "subscribed": 123,
  "tags": [
    {
      "id": 123,
      "name": "<string>"
    }
  ],
  "custom_fields": [
    {
      "id": 123,
      "type": 123,
      "value": "<string>"
    }
  ]
}