Let me start off by saying that I consider myself an advanced amateur with both API and JSON.
Where I am now
By importing CSV files I have a good handle on Insight and have a good idea of how I want to use it. Now I need to automate the import using PowerShell, but I am doing all testing in Postman as the PowerShell Insight module is no longer working.
I have a basic Insight Scheme set up:

I also have the import set up, key generated and working:

I am following along with this document: Insight external imports workflow (atlassian.com)
I am at the point where I am trying to set up mapping.
{
"status": "MISSING_MAPPING"
}
My current block:
My problem is that I can't get Insight to import any scheme I try, and I have tried a lot of variations and tried to search all over. I tried the two default schema files and get "
jsonValidationErrors" and when I tried to map my own very simple schema using those as templates, I get the same error.
{"jsonValidationErrors":[{"type":"required","code":"1028","path":"$","sc
hemaPath":"#/required","arguments":["schema"],"details":null,"message":"$.schema: is
missing but it is required"},{"type":"required","code":"1028","path":"$","schemaPath":"#/req
uired","arguments":["mapping"],"details":null,"message":"$.mapping: is missing but it is
required"}],"dataValidationErrors":[],"status":"error"}
If I can get the right format I could take it from there if anyone can help. However if I'm way off base in what I'm doing I would appreciate a pointer.
Right now I don't know what I need or how to format it and the examples are not explained and are very advanced at the moment with no context.
Any help?
Thanks for reading!