Prompt user with "Save as" option when exporting Selection of cells as PDF

I want to prompt the user with the SaveAs dialog when exporting a specific Selection of cells as a PDF. I found the method .SaveAs but I struggle to understand how to use it for a specific range of cells.

Private Sub Selection_promptSaveAs_PDF()

  
Dim file_name As Variant
file_name = Application.GetSaveAsFilename(FileFilter:="Adobe PDF File_ (*.pdf), *.pdf")

If file_name <> False Then
ActiveWorkbook.SaveAs Filename:=file_name
MsgBox "File Saved!"
End If
End Sub

The Selection object has a method for that:

Private Sub Selection_promptSaveAs_PDF()
    Dim file_name As Variant

    file_name = Application.GetSaveAsFilename(FileFilter:="Adobe PDF File_ (*.pdf), *.pdf")

    If file_name <> False Then
        Selection.ExportAsFixedFormat Type:=xlTypePDF, _
            FileName:=file_name, Quality:=xlQualityStandard, _
            IncludeDocProperties:=True, IgnorePrintAreas:=False, _
            OpenAfterPublish:=False
        MsgBox "File Saved!"
    End If
End Sub