Version 3

$postcode = "4680"
$body = "{`"operationName`":`"getProductAvailability`",`"variables`":{`"input`":{`"country`":`"AU`",`"postcode`":`"$postcode`",`"products`":[
{`"keycode`":`"43172382`",`"quantity`":1,`"isNationalInventory`":false,`"isClickAndCollectOnly`":false},
{`"keycode`":`"43485130`",`"quantity`":1,`"isNationalInventory`":false,`"isClickAndCollectOnly`":false}
],`"fulfilmentMethods`":[`"HOME_DELIVERY`",`"CLICK_AND_COLLECT`"]}},
`"query`":`"query getProductAvailability(`$input: ProductAvailabilityQueryInput!) {\n  getProductAvailability(input: `$input) {\n    postcode\n    country\n    availability {\n      HOME_DELIVERY {\n        keycode\n        poolName\n        stock {\n          available\n          __typename\n        }\n        __typename\n      }\n      CLICK_AND_COLLECT {\n        keycode\n        stock {\n          totalAvailable\n          __typename\n        }\n        locations {\n          fulfilment {\n            isBuddyLocation\n            locationId\n            stock {\n              available\n              __typename\n            }\n            __typename\n          }\n          location {\n            locationId\n            __typename\n          }\n          __typename\n        }\n        __typename\n      }\n      __typename\n    }\n    __typename\n  }\n}\n`"}"

$session = New-Object Microsoft.PowerShell.Commands.WebRequestSession
$r = Invoke-WebRequest -UseBasicParsing -Uri "https://api.kmart.com.au/gateway/graphql" `
-Method POST `
-WebSession $session `
-UserAgent "undefined" `
-Headers @{
"Accept" = "*/*"
  "Accept-Language" = "en-US,en;q=0.5"
  "Accept-Encoding" = "gzip, deflate, br, zstd"
  "Referer" = "https://www.kmart.com.au/"
  "Origin" = "https://www.kmart.com.au"
  "Sec-Fetch-Dest" = "empty"
  "Sec-Fetch-Mode" = "cors"
  "Sec-Fetch-Site" = "same-site"
  "Priority" = "u=4"
  "TE" = "trailers"
} `
-ContentType "application/json" `
-Body $body

$q = $r.Content | ConvertFrom-Json

$q.data.getProductAvailability.postcode
$q.data.getProductAvailability.availability.HOME_DELIVERY | ConvertTo-Json
$q.data.getProductAvailability.availability.CLICK_AND_COLLECT | ConvertTo-Json