How to create an array from multiple columns in csv file & pass that array to request body?

My question:
In postman, How to create an array from multiple columns in csv file & pass that array to request body?

Details (like screenshots):
In my case I used csv file and my request is post request which related to create template.
Here I pass some details regarding machines. But in csv have more than one machine details regarding each one template id.
So, I cannot run one test script for whole scenarios, because my request body is need to change regarding machine details.
Ex: for template id 1, there is one machines details. for template id 13, there is 3 machine details. like that.
this is my request body for one machine.

{
“projectTemplateName” : “PT1”;
“projectTid” : “000ab12”,
“blocks” : [
{
“mId_1” : “12”’
“tId_1” : “134”,
“requir_1”: “required”
}
]
}
This is my csv

So I hope to add functions to pre-request script. But I’m a beginner for postman. So, cannot find to how to start write the function?

I’m currently pass the data from csv to response and assert value in test tab.

How I found the problem:

I’ve already tried:

I’ve not done this myself but I think you could tweak what’s in this thread.
Mainly the .push option for appending an array.