Importing Knowledge Base articles into Helpy is a two step process.  The first step involves importing a list of categories, and a second import brings in the actual documents, with a pointer to one of your previously imported categories.  If you already have categories set up in Helpy, you can simply relate the pointer in the Docs import to existing categories through the category ID field.  If you do not, you must import categories before your import docs.

Categories 

Begin by importing categories.   The following data is required:

id (the ID of the category you are importing.  Start with at least 10)
name (the name of the category)

NOTE: If you are importing new categories, it is best to start with an ID of 10, as there are some system generated categories in the single digits that you will not want to overwrite.

A minimal CSV would look like this:

id,name
10,Category 10
11,Category 11

A sample template for Category imports can be found here: https://drive.google.com/drive/folders/1vjXWTLjkiCX6N5duTbJOlDm7dohL0btQ?usp=sharing

Docs

Once you have created or imported the categories, you can go ahead and import the docs, paying attention to associate each row with a category by matching up the category ID columns.

The following data is required to import replies:

category_id (the id of the category this doc belongs to)
title (the title of the doc)
body (the body of the doc)
user_id (the ID of the user who is the author of the doc)

A minimal CSV would look like this:

category_id,title,body,user_id
10,First KB Doc,This is the body,1
10,Second KB Doc,This is the body,1
11,Third KB Doc,This is the body,1

A sample import template can be found here: https://docs.google.com/spreadsheets/d/1sfVpPqkT-lHDXuUvuOa3Ah5Ti4WeQDES9tb11-trkUw/edit?usp=sharing