Export an Excel file using Laravel-Excel
The code looks OK. You may want to move the query outside of the foreach loop and group the results afterwards. But the foreach loop is limited to the number of days in a month, so I don't think that will do very much. That may cause the application to use more memory.

Therefore, I advise testing if the performance is indeed an issue. If so you might want to delegate creating the export to a queue. Queues in Laravel are not hard to implement (surprise!) 

Laravel Queues Documentation 7.x