I need help to unlock network for samsung galaxy tab 3 sm-T217S locked for sprint network

Since you're not a customer of Sprint it can't be unlocked.

Try doing an internet search for companies that provide unlock codes, but you will have to pay for the code.

The samsung galaxy tab 3 sm t217s don't have the phone app. how can i enter the unlock code if i get it?

Take it to one of those cellphone repair kiosks at your local shops.  One of them should be able to SIM unlock it for you for a fee.  

I begin learn phone repairing with my freind in his repair kiosk.

The client has take his galaxy tab 3 sm-t217s.

Thank you for help