define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true ); // or define( 'WP_DEBUG_LOG', '/tmp/wp-errors.log' )
define( 'WP_DEBUG_DISPLAY', true );

Source: https://wordpress.org/documentation/article/debugging-in-wordpress/

With wp_get_environment_type(): string one can get the current state of the project. It returns production by default, otherwise local, development or staging can be used.

It can be set in the wp-config.php file as :

define( 'WP_ENVIRONMENT_TYPE', 'development' );

Sources :

• https://developer.wordpress.org/reference/functions/wp_get_environment_type/
  
• https://make.wordpress.org/core/2020/07/24/new-wp_get_environment_type-function-in-wordpress-5-5/