how to get rid off image frame

That is most likely a border, applied in your theme’s CSS. Search for “img” in your stylesheet and then find border and remove.

If you can’t find it you need to post a URL of a page that has this issue, if you want someone to help you.

visual.gi/blog

actually img, its a link, but it doesnt has border attributes set

<p>
<div aling="left"><a href=https://www.plausive.net target="_new"><img src="https://visual.gi/blog/wp-content/themes/Visual/images/plausive.png" alt="Plausive"></a>
<p>
</div>

I didn’t find any images on the site you linked to, thus no example of your problem.

The border would be defined in the stylesheet, style.css, not in the IMG HTML tag.