how come I don't get a receipt after having my ring inspected and cleaned on 4/01/2019? how can I prove the ring was inspected for insurance purposes?

They keep a record of every time it is cleaned and inspected.

It sounds like what you're looking for is more so of an appraisal typically when insurance covers and inspection and a cleaning there's no receipt necessary however if you're going in and getting it cleaned and inspected for valuation purposes then that's an appraisal and of course you would get a receipt and you would be charged for such a service