CSS for Last Updated

Hi I have checked some of the previous posts, but none of the CSS I have tried is working.

I am trying to have the below in my posts based on the latest date I update the articles.

Last Updated DATE by: Author Name

Here is an example post: https://bullfightr.com/how-to-build-quality-wordpress-themes/

Is there some CSS I can utilize for this?

Currently it just says "by bullfightr"

Thanks in advance.