Change link to portfolio items

Hello nK. For a long time I was looking for a plugin that would allow me to create a gallery in the structure /[categoryname]/[sesionname], which is a kind of folder in the folder. In the end, I found and it is a Visual Portfolio. I would like to add that WordPress is a new thing for me and I must admit that the amount of knowledge I have already had to create even the simplest thing is very large for me. I managed to solve many problems myself, unfortunately I found one that was at a standstill.
Currently on the website I have a simplified model of what I would like to extend.
Main page is robertbuczabuczyn.com. There is a gallery created on it, which is really a copy of the invisible page robertbuczabuczyn.com/gallery (that link looks unnecessary, but in the future I want to make a category with movies and then robertbuczabuczyn.com/filmy will appear. If it was not /gallery, then the first level would not be divided into a type. Instead, the pictures would be “divided” into categories, and the films would still be on it).
After clicking the thumbnail with the category on the main page, we go to robertbuczabuczyn.com/gallery/sessions, which is just robertbuczabuczyn.com/galeria/[categoryname]. In this view, we already have individual photo sessions, so the links should be directed to robertbuczabuczyn.com/gallery /[categoryname]/[storyname], for example robertbuczabuczyn.com/galeria/sesje/daria. Unfortunately, the links go to robertbuczabuczyn.com/portfolio/[sesionname]. I was able to change the options that are on robertbuczabuczyn.com/galeria/[sesionname]. Then I went in “Direct links” and saved the changes to refresh the links. The side effect of this is that when you click a category, “page not found” appears. This is a problem, but it does not matter, because I still have not solved the problem.
Now the question – how could I do so that the portfolio items were at /gallery/ [categoryname]/[sesionname]? I found something like this https://wordpress.stackexchange.com/questions/94817/add-category-base-to-url-in-custom-post-type-taxonomy, unfortunately the amount of information contained in the post causes that I do not understand. I downloaded the “Custom Post Type Permalinks” plugin, which was recommended on that page, because the “visual” solutions will certainly be easier for me than the “code” ones. Unfortunately, despite this, I still do not understand anything and I do not know what to do, and I feel something that is very easy, but just need to know what to do.
If I wrote something unintelligible, I’m sorry. I will try to write in other words. I’m in a difficult situation where I have to write in a foreign language about things that I do not fully understand ??
Thank you for your help
Robert

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