Update _config.yml

_config.yml

@@ -48,7 +48,7 @@ sphinx:
           icon: fab fa-youtube-square
           type: fontawesome
       launch_buttons:
-        binderhub_url: https://hub.projectpythia.org
+        binderhub_url: https://binder.projectpythia.org/
         jupyterhub_url: https://projectpythia.2i2c.cloud
         notebook_interface: jupyterlab
       extra_navbar: |