Returns monthly usage statistics for all domains.

This endpoint returns monthly usage statistics for all domains, defaulting to data from the past six months, including the current month, when no parameters are specified.</br></br>Key features include:</br></br>- Clear success messaging: Returns a 200 success code with a confirmation message indicating the successful completion of the requested action.</br>- Comprehensive data retrieval: Returns a comprehensive monthly usage summary, providing a complete and accurate overview for seamless management and analysis.</br>- Comprehensive error handling: Returns 401 and 404 error codes with clear descriptions when requests fail.</br>- Periodic filtering: Uses the month and year parameters to filter results, enabling in-depth trend analysis, performance monitoring, and tailored reporting.