Adding full-width pictures to a blog post

Hello!

The theme I am currently using on my page (yuuta) does not support full-width pictures in the blog entry. The theme I am currently using does not have any sidebars and the text is centered. I would like the text to stay as it is, with some pictures within the entry stretching for the whole width of the browser (like in the case of the featured image in the blog entries in this theme). From what I noticed, themes which do support full-width picture close the content div, open a new div for the full-width picture and then open a new content div. Is there any way to make my theme do the same (or is there any other way to achieve that result)?

Here’s an example entry from my site: https://flyingsamovar.com/samovars-escape-to-st-pete/
Here’s an example of what I want to achieve: https://abito.fedeweb.net/demo/early-bird/ (the pelicans picture)

I will be extremely grateful for any help