Creating a 'foreach' style loop in pipelines

This should give you a good start. To me as long as you understand a little Jinja and API this is the easiest route to go. You may have to adjust depending on what data you're creating the records with. Such as date formatting or casting to a certain data type. 

Step A: Trigger, with field for quantity of records to create
Step B: Make a Request
URL: https://api.quickbase.com/v1/records
Method: POST
Content type: application/json
Body: 

{
  "to": "tableId", {# Table Name #}
  "mergeFieldId": 3, {# Your Key Field - only needed if you're going to update records, not create new #}
  "data": [ {% for x in range(a.counter_field) %}
    {
       "FID": { {# Foreign Key #}
        "value": "{{a.field_label | int}}" {# I always cast numeric foreign keys to an int #}
      },
      "FID": { {# Field Label#}
        "value": {{a.field_label}}
      },
      "FID": { {# Field Label#}
        "value": {{a.field_label}}
      },
      "FID": { {# Field Label#}
        "value": "{{a.field_label}}"
      }
    }
  {% if loop.last == false %},{% endif %}
  {%- endfor %} 
  ]
}