Problems using Invoke-PowerBIRestMethod to update parameters

Hi Dom87326,

Are "%Date" and "%Customer" the actual paramater name? And the names were originally preceded by a prefix "%"? Is the date type of "%Date" Text type or Date type? Could you please refer the following thread to change the codes as below and check if it can work....

Update parameters through Powershell

#Group ID and Dataset ID 
$urlbase = "groups/4bc15b4f-5dc8-49e3-aaba-XXXXXXXXXXXX/datasets/AAAAAAAA-YYYY-4cb8-898a-222261a5e0d0/"

$body = '{
	updateDetails: [
    {
      "name": "%Date",
      "newValue": "11111111"
    },
    {
      "name": "%Customer",
      "newValue": "Amazon"
    }
   ]
}'

#url and body for UpdateParameters in API call
$url = $urlbase + "Default.UpdateParameters"

$content = 'application/json'

Invoke-PowerBIRestMethod -Url $url -Method Post -Body $body -ContentType $content

Best Regards