Help with Rest API call (POST) with parameters and CSV attachment

Hello Team,

please can someone help me in the below.

I'm trying to call a Rest API below specification working in postman, and receiving perfectly the response: 

POST /PharmacyServices/api/Pharmacy/Upload?Key=aaaa&Username=bbb&Password=ccc HTTP/1.1
Host: abc:38440
Content-Length: 240
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="File"; filename="///xxxx/POC/CSV/20230607.csv"
Content-Type: text/csv

(data)
------WebKitFormBoundary7MA4YWxkTrZu0gW--

Here's what i'm trying to do in IRIS:
 

Set docpath = "\\xxxx\MediTrack\" _ pRequest.FileName _ ".csv"
 
try{
     Set HttpRequest = ##class(%Net.HttpRequest).%New()
    
    set HttpRequest.Server=..Adapter.HTTPServer
set HttpRequest.Port=..Adapter.HTTPPort
     //set HttpRequest.ProxyServer=..Adapter.ProxyServer
     //set HttpRequest.ProxyPort=..Adapter.ProxyPort
     set HttpRequest.ProxyTunnel=..Adapter.ProxyHttpTunnel
     set HttpRequest.ProxyHTTPS=1
     set HttpRequest.SSLConfiguration=..Adapter.SSLConfig
    
    
 Do HttpRequest.SetHeader("Accept", "'*/*'")
     Do HttpRequest.SetHeader("Access-Control-Allow-Origin","*")
 
set stream=##class(%Stream.FileCharacter).%New()
set sc=stream.LinkToFile(docpath)     
Set RootMIMEPart = ##class(%Net.MIMEPart).%New()
Set BinaryMIMEPart = ##class(%Net.MIMEPart).%New()

Set BinaryMIMEPart.Body = stream
Do BinaryMIMEPart.SetHeader("Content-Type", "text/csv")
Do BinaryMIMEPart.SetHeader("Content-Disposition","form-data; name=""File""; filename="""_docpath_"""")

S status = RootMIMEPart.Parts.Insert(BinaryMIMEPart)

Set writer = ##class(%Net.MIMEWriter).%New()
Do writer.OutputToStream(HttpRequest.EntityBody)
Do writer.WriteMIMEBody(RootMIMEPart)

Do HttpRequest.SetHeader("Content-Type", "multipart/form-data; boundary="_RootMIMEPart.Boundary)
Do HttpRequest.SetHeader("Content-Disposition","form-data; name=""File""; filename="""_docpath_"""")    
  Do HttpRequest.SetParam("File", BinaryMIMEPart)

set tSCx = HttpRequest.Post(tURL, 0, 1)   If '$IsObject( HttpRequest.HttpResponse) {
         s err = "Response Error"
$$$TRACE(err)
  }
 
Set Myresponse = HttpRequest.HttpResponse
 
If $IsObject(Myresponse) {
set data1 = ""
set stream1 = Myresponse.Data
While 'stream1.AtEnd { 
set data1 = data1 _ stream1.ReadLine(,.sc,.eol)
If $$$ISERR(sc) { set data1 = data1 _ "ERROR" Quit } 
}
$$$TRACE(data1)
}
 

But i'm receiving an error from the API stating that:

Invalid 'HttpContent' instance provided. It does not have a content-type header value. 'HttpContent' instances must have a content-type header starting with 'multipart/'.Parameter name: content"

Any idea what should be changed?