Those items in the following are that I've met the use of external API in the Adalo.
  1. If the response is null, Adalo cannot handle this field and set it to the external collection.
  2. Timestamp data type in the response. Adalo handles those fields as numeric over the date.
  3. Adalo cannot handle the error message that comes from the external API.
  4. Adalo cannot handle the boolean data type that comes from the response.