How can I get a post to show up for a specific plugin??

I'm confused because I'm having difficulty figuring out how to use WPMUDEV.org forum, to place a post/question, for a specific plugin, etc. Can you explain.

For example, I posted a question at https://premium.wpmudev.org/forums/topic/how-can-i-edit-or-customize-the-pages-in-marketpress-such-as-products-and-the-individual-product-pages that I'm trying to get answered.

Thanks,
Gary