Compile error adding picture to powerpoint?

Part way through building a routine which generates a pre-formatted presentation file. Getting a compile error: Argument not optional at the point of inserting a picture.

Any help greatly appreciated.

Sub CreatePresentation()

    'Declarations
    Dim pptApp As PowerPoint.Application
    Dim pptPres As PowerPoint.Presentation
    Dim strFile As String
    Dim pptSlide As PowerPoint.Slide
    Dim pptShape As PowerPoint.Shape
    Dim strPathname1, strPathname2, strPathname3, strPathname4, strPathname5, strPathname6, _
    strPathname7, strPathname8, strPathname9, strPathname10, strPathname11, strPathname12, _
    strPathname13, strPathname14, strPathname15, strPathname16, strPathname17, strPathname18, _
    strPathname19 As String
    Dim ClientFolder, ClientCode, ClientNo As String
    Dim ImageTitle1, ImageTitle2, ImageTitle3, ImageTitle4, ImageTitle5, ImageTitle6, ImageTitle7, _
    ImageTitle8, ImageTitle9, ImageTitle10, ImageTitle11, ImageTitle12, ImageTitle13, ImageTitle14 _
    , ImageTitle15, ImageTitle16, ImageTitle17, ImageTitle18, ImageTitle19 As String

    
    'Statements
    strFile = "C:\Users\Desktop\Presentation.ppt"
    
    ClientFolder = "C:\Users\Sheets("SourceData").Range("B6").Value
    ClientCode = Sheets("Quotation").Range("c426").Value
    ClientNo = Sheets("SourceData").Range("B6").Value
    
    ImageTitle1 = ClientNo + "_Survey1.jpg"
    'ImageTitle2 ...etc

    strPathname1 = ClientFolder + "\SURVEY NOTES\" + ImageTitle1
    'strPathname2 ....etc    

    'Actions
    Set pptApp = New PowerPoint.Application
    pptApp.Visible = True
    Set pptPres = pptApp.Presentations.Open(strFile)
    pptApp.Activate
       
    'Process
    
    On Error Resume Next
    With pptPres.Slides(1)
        .Select
        .Shapes.AddPicture Filename:=("strPathname1,msoCTrue, msoCTrue") 'Compile Error highlights ".AddPicture"
    End With
    
    
    'Set pptApp = Nothing

End Sub