use IlluminateSupportFacadesLog;
// Severity levels base on RFC5424 commented on the right side
Log::emergency($message); // system is unusable
Log::alert($message); // action must be taken immediately
Log::critical($message); // critical conditions
Log::error($message); // error conditions
Log::warning($message); // warning conditions
Log::notice($message); // normal but significant condition
Log::info($message); // informational messages
Log::debug($message); // debug-level messages
// Checkout RFC5424 here - https://tools.ietf.org/html/rfc5424
Log::info('This is some useful information.');
Log::warning('Something could be going wrong.');
Log::error('Something is really going wrong.');
Ensure debug mode is on - either add APP_DEBUG=true to .env file or set an environment variable
Log files are in storage/logs folder. laravel.log is the default filename. If there is a permission issue with the log folder, Laravel just halts. So if your endpoint generally works - permissions are not an issue.
In case your calls don't even reach Laravel or aren't caused by code issues - check web server's log files (check your Apache/nginx config files to see the paths).
If you use PHP-FPM, check its log files as well (you can see the path to log file in PHP-FPM pool config).