Sir,
I have analyzed the documentation part, but the problem is that the message part has not been developed.
For example, I once applied with a coupon code and I am trying to use my coupon code. The message that I have just applied with this coupon code should appear.
The message will appear when the coupon code expires. If I have created a coupon code so that the expiration date is March 31 and I am applying with this coupon code, the time of the coupon code has expired and the discount cannot be realized.
A message should be displayed for each action so that the client is notified, not only the status 200 is returned for each request and the client is not aware of what is happening.