REST API create object with upload field

Hi, I'm trying to create a new object in a collection containing an upload field.

The collection has approximately the following model:

submissions {
  message: text,
  attachments: upload
}

In order to create a new object with attachments, I do the following:

I create all the uploads first using the REST interface and I save the resultant

s in a list.

I then make a create (POST) request to the collection endpoint with the following JSON body:

{
  message: string,
  attachments: string[] // These are the doc.id's 
}

The issue I'm having is that every time I try to pass the list of ids, I get the following error:

{"errors":[{"name":"ValidationError","message":"The following field is invalid: attachments","data":[{"message":"This field is not a valid upload ID.","field":"attachments"}]}]}

When I manually check the ids, I see that they are in fact the right ideas for object within the uploads collection.

What am I doing wrong?

I figured it out! Sorry for clogging up the forum! I forgot to put the upload field in an array field. To actually push I mapped the ids to

and now everything works fine!