For accessing easily, the theme, site or brand logo markup block is well commented with the text "logo". Simply search for it in your code editor. This will take you to a block similar to the below example:

<!-- Brand Logo-->
<div class="brand-logo">
    <!-- light version logo (logo must be black)-->
    <img src="image/logo.png" alt="" class="logo-light">

    <!-- Dark version logo (logo must be White)-->
    <img src="image/logo-v2.png" alt="" class="logo-dark">
</div>

The logo.png is for light mode and The logo-v2 is for dark mode.

Replace the src attribute path according to your brand/company logos.