Posting Json array through Web Request - Custom Object

Hi, I’m attempting to update a custom object using a Web Request.
The Custom Object is a list of group names retrieved from our on prem AD using the orchestrator. (This piece works fine).
How can I add the array of group names to the Web Request?
Currently I have this in the body:

{
  "data": {
    "bo_created_at": "2023-12-05T09:47:52.148Z",
    "bo_created_by": "54000889652",
    "bo_display_id": "1",
    "bo_updated_at": "2023-12-05T09:47:52.148Z",
    "bo_updated_by": "54000889652",
    "project_name": [
      "TEST456",
      "TEST564"
    ]
  }
}

The response

{  "error": {    "error_type": "INVALID_INPUT",    "message": "Invalid input",    "errors": [      {        "name": "project_name",        "message": "Data is missing for required field"      }    ]  }}

The request works fine for individual values. e.g

{
  "data": {
    "bo_created_at": "2023-12-05T09:47:52.148Z",
    "bo_created_by": "54000889652",
    "bo_display_id": "1",
    "bo_updated_at": "2023-12-05T09:47:52.148Z",
    "bo_updated_by": "54000889652",
    "project_name": "TEST456"
  }
}

Can anyone confirm whether I have submitted this in the correct forum or not?
Was hoping for a response

What is the data type in that custom object? From what I can tell, there does not appear to have one-to-many relationships. Dropdowns and lookups allow a single object to be selected. There would be one row created for each project. Are you seeing the capability in the GUI to be able to make a multi-select\multi object selection? If you are attempting to store multiple items in a row property, it would likely be a delimited string that would need to be parsed to an array with a split function.

Hi Rob,

It’s a text data type.
It’s a standard object with one entry per row. I’m trying to insert multiple rows against the same object at once.

Do not think that capability exists. It would be a foreach logic, pseudo code example:

$projects =  "TEST456","TEST564"

foreach ($project in $projects) {

$body = @"
{
    "data": {
      "bo_created_at": "2023-12-05T09:47:52.148Z",
      "bo_created_by": "54000889652",
      "bo_display_id": "1",
      "bo_updated_at": "2023-12-05T09:47:52.148Z",
      "bo_updated_by": "54000889652",
      "project_name": $($project)
    }
  }
"@

    Invoke-WebRequest -Body $body ...

}