Notice: register_rest_route was called incorrectly. The REST API route definition for
if-menu/v1/did-you-made-this-request is missing the required
permission_callback argument. For REST API routes that are intended to be public, use
__return_true as the permission callback. Please see Debugging in WordPress for more information. (This message was added in version 5.5.0.) in /home/$username/public_html/wp-includes/functions.php on line 5225
This error usually occurs when in PHP settings, display errors is enabled. This indicates that some of your Theme or plugin of WordPress is using old or non compatible functions which are no longer supported by WordPress.
Also, This is a warning message only and is not an actual error.
In such cases , you can identify which theme or plugin is causing the issue and you can contact theme or plugin author to fix this issue.
If you want to get rid of this notice , you can change
define( ‘WP_DEBUG’, true ); to define( ‘WP_DEBUG’, false );
in your wp-config.php file .