问VBA请求文字报错check content-type and body？

Sub 文字识别()

strPicPath = Application.GetOpenFilename(, , "打开图片") '打开文件

EncodeFile (strPicPath)

End Sub

Public Function EncodeFile(strPicPath As String) As String

Const adTypeBinary = 1

Dim objXML

Dim objDocElem

Dim objStream

Set objStream = CreateObject("ADODB.Stream")

objStream.type = adTypeBinary

objStream.Open

objStream.LoadFromFile (strPicPath)

Set objXML = CreateObject("MSXml2.DOMDocument")

Set objDocElem = objXML.createElement("Base64Data")

objDocElem.DataType = "bin.base64"

objDocElem.nodetypedvalue = objStream.Read()

EncodeFile = objDocElem.text

appid = "{""appid"":""""," '云API密钥中查看

Image = """url"":""https://tac-wzhq398961275745398-ho-1253637748.cos.ap-beijing.myqcloud.com/20181022145648.jpg""}"

Image = """image"":""" & objDocElem.text & """}"

URL = "http://recognition.image.myqcloud.com/ocr/general"

With CreateObject("msxml2.xmlhttp")

.Open "POST", URL & "?", False '

.setRequestHeader "Host", "recognition.image.myqcloud.com"

.setRequestHeader "Content-Type", "application/json"

.setRequestHeader "Authorization", ""

.send appid + Image

End With

Set objXML = Nothing

Set objDocElem = Nothing

Set objStream = Nothing

End Function

画横线的两行代码是定义图片的，第一行是图片连接，识别成功，第二行是定义图片base64编码的，识别报错了，请帮忙看看，错在哪里，是不是图片定义写法有问题

错误代码{"code":3,"message":"invalid request: parsing error - check content-type and body","data":{ "session_id":"10390471565310750" }}