API_ImportfromCSV doing nothing

Hi all!

I'm trying to run this API_ImportfromCSV but it's getting me nowhere. 
I'd appreciate some help as I've been stuck with it for many hours, and haven't gotten to my error.

https://(DOMAIN).quickbase.com/db/(TABLE)?a=API_ImportFromCSV&usertoken=(USERTOKEN)&apptoken=(APPTOKEN)&records_csv=Guia,34168,102999&clist=6&skipfirst=1

This should create new records in the table when the API is run. 
Added "apptoken" as the API returned an error even when using usertokens.
Everything seems to be fine, but the reply is: 

<qdbapi>
<action>API_ImportFromCSV</action>
<errcode>0</errcode>
<errtext>No error</errtext>
<num_recs_input>0</num_recs_input>
<num_recs_added>0</num_recs_added>
<num_recs_updated>0</num_recs_updated>
<num_recs_unchanged>0</num_recs_unchanged>

</qdbapi>

Nothing seems to happen!
I've tried doing this from google scripts, as I want to automate the import but this also doesn't seem to work.. I have the values I need for the CSV in an array, which i'm joining using

    var csvString = "Guia," + arregloGuias.join(",\n");      var url = baseURL + table + "?a=API_ImportFromCSV" + usr_token + apptoken;
    var options =
      {
        "method"  : "POST",
        "records_csv" : csvString,
        "clist" : "6",
        "skipfirst": "1"
      };
  Logger.log(url + options);
  var result = UrlFetchApp.fetch(url, options);
  Logger.log(result);

The result is the same

<?xml version="1.0" ?>
<qdbapi>
<action>API_ImportFromCSV</action>
<errcode>0</errcode>
<errtext>No error</errtext>
<num_recs_input>0</num_recs_input>
<num_recs_added>0</num_recs_added>
</qdbapi>

Appreciate any help!!

Thanks!