The issue turned out to be a bug.
When I created the API it wasn’t showing up on the Workflow Screen, so this prevented me from doing any further mapping to create a Data Thing.
Finally I thought to just create a new API and then it showed up. Go figure. Sometimes you just have to bash at a system or start over to get it to behave properly.
As for my question then, the answer is:
Create a new API
GET call with JSON type data
Enter the API Endpoint
Initialize API (check that it works, you should see the structure of your API response)
Create a New Event (any event you want)
Create new Thing > Select Table you want to write Data to.
(in my case its a table called Job)
THIS IS KEY
for each field in your Table, you need to define the source.
Choose External API > then choose your NEW API that you created (this wasn’t showing before, so if you don’t see your API, delete the old one and start over… this is a bug)
Then for each Field, you need to map it to the API… your API may have a nested structure, so for example my API I needed to select
API > Data > Group > Link URL > :first item > text
Data - because this is the block that contains the payload
Group - because the payload is structured for possible repeating items
Link URL - this is the actual bit of data I was looking for (but not done yet!)
:first item - is a directive to take the first item in the group list. Since there was only one item its not a problem
text - is the data type that I defined in the API Builder to match my Job Table.
Data types must match.
This was not at all clear or easy and required significant experimentation. The Manual use case (and forum posters) only tell you how to post the data to a Page for on demand use, however my use case required us to store the data in a table so we could further analyze it and use it for future transactions.
Writing data from an API to a Database should be pretty straight forward and it can be once you have the API response AND are able to properly see the API Response is available on the Workflow Screen.
Good luck anyone else attempting this use case.