Assuming the named folder exists and the bookmarks both exist and have content and there are no illegal filename characters in either bookmark (all of which should really be error trapped) then:
Code:
Private Sub CommandButton1_Click()
Const strPath As String = "C:\Users\sesa460426\Box Sync\My Projects\Quotes\"
Dim strName As String
On Error Resume Next
strName = ActiveDocument.Bookmarks("ClientName").Range.Text
strName = strName & ActiveDocument.Bookmarks("QuoteNumber").Range.Text
If Not strName = "" Then
strName = strName & ".pdf"
ActiveDocument.ExportAsFixedFormat OutputFileName:= _
strPath & strName, _
ExportFormat:=wdExportFormatPDF, _
OpenAfterExport:=False, _
OptimizeFor:=wdExportOptimizeForPrint, _
Range:=wdExportAllDocument, _
From:=1, to:=1, _
Item:=wdExportDocumentContent, _
IncludeDocProps:=True, _
KeepIRM:=True, _
CreateBookmarks:=wdExportCreateNoBookmarks, _
DocStructureTags:=True, _
BitmapMissingFonts:=True, _
UseISO19005_1:=False
End If
End Sub