If $blog_url is coming from a WordPress theme/plugin, you usually can’t change it directly from the normal WordPress admin unless the developer made it an editable setting.

Check these places:

  1. WordPress Admin → Settings
    • Look for something like Blog, Reading, or Theme Settings.
    • Go to Settings → Reading and check the Posts page setting. This is commonly where the blog/archive URL comes from.
  2. Appearance → Customize
    • Look under Theme Options, Homepage Settings, Menus, etc.
    • The link may be configured there.
  3. Pages → All Pages
    • Find the page you want the “Browse all articles” button to point to.
    • If it’s the WordPress posts archive, check Settings → Reading → Posts page.
  4. If none of those contain it
    • $blog_url is probably being generated in PHP, e.g.: