TMD using etabs. How to model it on etabs?

[Justiboss]

Hi. I need to assign TMD to my structure. I have modeled the structure in etabs, but i dont know how to assign the tmd.

I know it has something to do with link properties. But i dont know exactly how to do it. Also how to add the mass? Using additional point mass?

And should the tmd element be drawn by choosing NONE as the elemnt?
Thank you very much. This is really important.
I really appreciate it.