Dear dixibru,
Thanks for your post.
Please be kindly informed that the number of images per row depends on your theme container. From provided screenshots, we can see that now you have only one image in a row and this kind of organization of images on the page probably is referred to your theme’s container width.
In any case, it worth to be noted that the width and height of images can be changed from general options in the commercial version of the plugin and they will be automatically arranged on the page, taking the space provided by your current theme.
May we kindly ask you to provide the link to your website where the gallery is added and we will check if your theme allows having more than one image per row? If your website is not yet live, you can try to check that on your own: press F12, select an element in the page to inspect it https://prntscr.com/fu6s3a and hover over the gallery. Highlighted blue space will be your theme container: https://prntscr.com/fu6syw
Please let us know if there are other questions you have regarding this option or any other one related to our plugin and its functionality.
We will be happy to assist.
Thanks