Hi, you’d want to first create a child theme ( https://developer.www.ads-software.com/themes/advanced-topics/child-themes/ ) in the event that any updates to the theme in the future won’t overwrite changes you make.
Once you have the child theme created, copy the header.php file into your child theme. With your child theme activated, open up the theme editor and navigate to the header.php page. You’ll want to modify part of the following line of code
<button class="menu-toggle" aria-controls="primary-menu" aria-expanded="false"><?php _e( 'Menu', 'argent' ); ?></button>
The only thing you should change in this is the word Menu in between the '. As you are using the theme editor, it is possible that if you remove one of those single quotation marks and try to save your changes you’ll break the site. As an example, if you wanted to change it from Menu to Navigation you would modify the code as follows
<button class="menu-toggle" aria-controls="primary-menu" aria-expanded="false"><?php _e( 'Navigation', 'argent' ); ?></button>
