Go to the html file and search for the navbar-brand.

                        
<a class="navbar-brand" href="index.html">
    <!-- Logo icon -->
    <b class="logo-icon">
        <!--You can put here icon as well // <i class="wi wi-sunset"></i> //-->
        <!-- Dark Logo icon -->
        <img src="../../assets/images/logo-icon.png" alt="homepage" class="dark-logo" /> <!-- Put Dark color Logo Icon -->
        <!-- Light Logo icon -->
        <img src="../../assets/images/logo-light-icon.png" alt="homepage" class="light-logo" /> <!-- Put Light color Logo Icon -->
    />
    </b>
    <!--End Logo icon -->
    <!-- Logo text -->
    <span class="logo-text">
        <!-- dark Logo text -->
        <img src="../../assets/images/logo-text.png" alt="homepage" class="dark-logo" /> <!-- Dark Logo icon Text Here -->
        <!-- Light Logo text -->
        <img src="../../assets/images/logo-light-text.png" class="light-logo" alt="homepage" /> <!-- Light Logo icon Text Here -->
        />
    </span>
</a>
                        
                    

Put the image in assets -> images Folder.