Help editing user card

Hi, i am new to Discourse, and i am developing a theme; i have to modify the user card and i don’t know what the best way to do this is; I have to visualize some custom fields on the top of the card (under the title), but i am not able to do this through a plugin outlet, because i don’t have the publicUserFields parameter.
Can you please link some documentation or some examples on how to do this and the best practices?

Thanks in advance