Extract image from http response and save it to local folder

Sub GetImg()
    Dim MyRequest As Object
    Dim ByteArray() As Byte
    Dim FileNum As Integer
    Dim FilePath As String
    Dim FileName As String

    ' Create the request
    Set MyRequest = CreateObject("WinHttp.WinHttpRequest.5.1")
    MyRequest.Open "GET", "https://<provider addr>?text=<instruction for image>", False
    MyRequest.Send

    ' Check if the content type is image/png
    If InStr(1, MyRequest.GetResponseHeader("Content-Type"), "image/png", vbTextCompare) > 0 Then
        
        ' Get binary response body
        ByteArray = MyRequest.ResponseBody
        
        ' Create file path in the same folder as the workbook
        FileName = "downloaded_image_" & Format(Now, "yyyymmdd_hhnnss") & ".png"
        FilePath = ThisWorkbook.Path & "\" & FileName
        
        ' Save binary data to file
        FileNum = FreeFile
        Open FilePath For Binary As #FileNum
        Put #FileNum, , ByteArray
        Close #FileNum
        
        MsgBox "Image saved to: " & FilePath
    Else
        MsgBox "Response was not an image. Content-Type: " & MyRequest.GetResponseHeader("Content-Type")
    End If
End Sub

Since your response is a binary .png image, and you're getting it via a WinHttpRequest, you need to work with the binary response body, not ResponseText.

Hope this helps you.