Thanks Guys,
Here's what I had to change to make it work:
a) replaced single quotes (') with escaped double quotes (")
b) Set a variable to the data JSON and inserted @$JSONVariableNameHere into place of the explicitly quoted JSON.
I experimented with keeping or removing the HTTPS text to the right of POST and found that including or removing it made no difference in the result so I'm removing that text in respect for the KISS principle.
Likewise, it was not necessary to put --location on its own row as one reply seemed to suggest. I suspect that I can remove that cURL option completely and only put it here, because postman inserted that option when I copy/pasted the sample code from the site's API documentation.