In the rich text editor:
@Amity
In a comment:
[Amity](https://chowlings.com/user/Amity)
For Names and Avatars:
In the rich text editor:
%Amity
In a comment:
[![Amity's Avatar](https://chowlings.com/images/avatars/384.jpg?v=1645136821)](https://chowlings.com/user/Amity) [Amity](https://chowlings.com/user/Amity)