How to add logo as blog name instead of text

The only way to help you is to see how your theme is coded if you can paste your header.php file in https://wordpress.pastebin.com and then paste url here from paste bin so we can help.

Upload your png file to WordPress media.

Then edit your themes style.css file : https://cl.ly/image/1K1Y303b1E3c

…to include something like this: https://css-tricks.com/header-text-image-replacement/

The key is the background:url styling

https://pastebin.com/uvRcAGc4

You have this in your code

<?php
                                if(get_header_image()){
                                        ?><img src="<?php header_image(); ?>" height="<?php echo get_custom_header()->height; ?>" width="<?php echo get_custom_header()->width; ?>" alt="<?php print esc_attr(get_bloginfo('name')) ?>" /><?php
                                }
                                else{

I have tried to add the image using Appearance>>>>Header