Display posts by the current category

Hello!

I have created a section to show related posts and it´s working normally! I´m trying to filter the results showing just the posts of the current category of the post, so i tried this:

I have created a shortcode post_cat to return the current category and put it inside with documentation “settings” instructions:

[wp_show_posts id=”9855″ settings=”taxonomy=category&tax_term=[post_cat]”]

But i saw that this approach doesn´t work…

How could this work?

Thanks and Regards,
Tony