Is this sentence correct?
since the last two weeks, I have spent 30 hours and my employer approved the timesheet. I'd appreciate it if you could send them an invoice. Also, The timesheet has been attached here.

Question

Answer

I’m assuming you’re talking about how many hours you’ve been working;

In the last two weeks I have worked 30 hours, and my employer has approved the timesheet. I would appreciate it if you could please send them (who, the employer?) an invoice. Please see the attached timesheet.