how to show full post instead of excerpts on category page

I have set up three category pages on vivianadaya.com but by default only the titles comes up. I’d like to modify this so that these three pages show full posts.

I did follow an older thread on the subjet but had no luck as you can see on this thread :

https://www.ads-software.com/support/topic/category-page-dissaeapred-after-trying-to-get-full-post-instead-of-excerpt?replies=6

How do I proceed to modify this default setting for category pages?