mean stack backend

R_5. Paying through an online()
F_5.1. The system shall allow the user to be able after selecting his locker to proceed to an online payment method.(not an actual gest a skeleton)
R_6. Confirm the payment()
F_6.1. The system shall confirm the payment and give access to the user to gain his locker.
R_7. Provide a passcode()
F_7.1. The system shall provide a specific barcode of four digits for each user to unlock his locker.
R_8. Sending notification()
F_8.1. The System shall send a notification to the user telling how many days are left for his locker to expire or if the locker has a malfunction. F_8.2.The system shall send a notification to the admin that updates him if a locker has a malfunction.
R_9. Receiving notifications via email()
F_9.1. The system shall allow the user to receive a notification each time he register that updates him the locker period left for its renting ownership to expire or if there is a malfunction in the locker.
F_9.2. The system shall allow the admin to receive a notification via email that updates him if a locker has a malfunction
f-9.2 the system should detect the type of the card