Hi @dunderkind,
you cannot use the external collection because the API does not deliver a REST API response. Meaning there are no brackets for an array.
Good new is:
You can use the freshly announced custom actions outputs.
See: Custom Action Outputs are Live!
I created a draft dummy you can clone from: Corona PH API
Note this is DRAFT just to show the API!
Check the Get Data button on the Home screen:
Get the data
Save the returened data
In this setup there will be a new record created each time the users clicks the button.
I did not solve how to just keep one record updated with the last request in this draft demo.