Level "100" is not defined, use one of: 100, 200, 250, 300

I am having the issue when installing the module if I have handler defined like this:

services:
  monolog.handler.rotating_file:
    class: Monolog\Handler\RotatingFileHandler
    arguments: ['private://logs/drupal.log', 10, '%monolog.level.debug%']

The error I am getting
You have requested a non-existent parameter "monolog.level.debug".