Employers are allowed to request that you sign over your jury duty check to them if you are paid for your time off. it's a way to dissuade people from claiming they have jury duty to get free PTO days

If you have already told your job you have jury duty you need to show up to get the check for the day. You can't call and ask the jury office for a check because you didn't show up and now your boss is asking for it as proof that you actually had jury duty.