magento2.2.6 – how to show 4 products in all categories

I have tried all the tricks on the web (stackexchange, YouTube videos, search engines, forums and communities).

what I want to achieve is
1) I do not want to show anything (there are no columns on both sides)
2) 4 products in a row, which is derived from the category.

1) So far I have only managed to reach the element 1. going to category> design and selecting 1 column (see image for reference). It shows only products (I'm not sure if this is the correct way).

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2) I have tried all the options in cpanel. I have also tried editing .css.

Is there any way to do it through the administration control panel?
through css (in any other way).