How to generate 'UNA:+.?*'' the first line of EDI D960A format

Question

In EDI D960A format the first line is below

UNA:+.?*'

How to generate this line using EdiTools nuget package in C#.

I already this below line of code.

            var una = new EdiTools.EdiSegment("UNA");
            una[01] = ":+.?*";
            ediDocument.Segments.Add(una);

But upper code generate this line below

UNA>+. 

Please suggest the possible code.