Create JSON.stringify payload from Google Sheets Cells - json

Question

I have a script that will post available stock adjust to Shopify but I don't know how to extend that and get the payload from cells in the sheet and ideally loop the payload so I can update more than one item at a time.
REF: https://shopify.dev/docs/admin-api/rest/reference/inventory/inventorylevel#adjust-2021-01
I want to have cells in the sheet for "location_id", "inventory_item_id", "available_adjustment" and loop these so I could have below for example.
"location_id"
"inventory_item_id"
"available_adjustment"
11594563
34516664746035
1
11595526
34516664746851
-1
11215528
34516664567861
5
11595574
34516664745685
6
This is the current script that is working but I need to manually change the payload and run one at a time where I want to be able to adjust a lot more in one hit.
var url = "https://**********.myshopify.com/admin/api/2021-01/inventory_levels/adjust.json";
var payloaddata = {
"location_id": "11594563",
"inventory_item_id": "34516664746035",
"available_adjustment": "-1"
};
var payload = JSON.stringify(payloaddata);
var username = "*********";
var password = "*********";
var response = UrlFetchApp.fetch(url, {
method: "POST",
payload: payload,
contentType: "application/json",
headers: { "Authorization": "Basic " + Utilities.base64Encode(username + ":" + password) }
});
Logger.log(response.getContentText());
var json = response.getContentText();
var data = JSON.parse(json);
Logger.log(data);
} ```

Answer 1

Assuming that your code is working then try this:
I also assume that you spreadsheet looks like your table with same headers and same order of columns
function shopifyPost() {
const ss = SpreadsheetApp.getActive();
const sh = ss.getSheetByName('Sheet Name');
const [hA, ...rows] = sh.getDataRange().getValues();
const url = "https://**********.myshopify.com/admin/api/2021-01/inventory_levels/adjust.json";
rows.forEach((r, i) => {
let pld = {};
pld[hA[0]] = r[0];
pld[hA[1]] = r[1];
pld[hA[2]] = r[2];
let payload = JSON.stringify(pld);
let username = "*********";
let password = "*********";
let response = UrlFetchApp.fetch(url, {
method: "POST",
payload: payload,
contentType: "application/json",
headers: { "Authorization": "Basic " + Utilities.base64Encode(username + ":" + password) }
});
});
Logger.log(response.getContentText());
var json = response.getContentText();
var data = JSON.parse(json);
Logger.log(data);
}
The first line looked like this: (after stringifying it)
{"location_id":11594563,"inventory_item_id":34516664746035,"available_adjustment":1}
This is what my data sheet looked like:
location_id
inventory_item_id
available_adjustment
11594563
34516664746035
1
11595526
34516664746851
-1
11215528
34516664567861
5
11595574
34516664745685
6