The instructions link to a youtube video about TextMeshPro from 5 years ago! It does not seem to be relevant to this version of Unity. I can get the billboard to display an imported graphics asset (.jpg) but no joy getting it to display any text.
“Use TextMeshPro to use text instead of an image for the billboard”
Me too 
I found it!
Someone called John Coletta found a way to do it. He says:
TextMeshPro took me a while to understand. For those who are having trouble. Create a gameObject as a child to Billboard. Then add the TextMesh Pro component. From there resize it on the Billboard as you see fit. Happy learning!
I am not able to get this to work. When I place a Billboard object from the MOD Resources, there is a Billboard Content child object available. When I try to add component I have 3 options “TextMeshPro - Inputfield”, “TextMeshPro - Text” and "“TextMeshPro - Text(UI)”. when I try to add any of the above 3, it gives me an error message.
Do I need to add “mesh renderer” first before I add anything else? I tried this…still didnt work.
I am able to add “Text Mesh” after I add “Mesh Renderer”, but I am not sure, if that is the right solution.
Did you get a solution for this?
me too
I’m having trouble with this as well.
I see that someone posted how to do it, I tried the suggestion but it’s not working for me. Is there any way to show a screenshot of how the hierarchy looks? I can not get this to work.
Thanks for any help
And still, the 2D forum is NOT related to UI. The correct and dedicated forum for this is here.