appends data to the service URL.
But its size shouldn’t exceed the maximum URL length.
However,  doesn’t have any such limit.
So, theoretically, a user can pass 
unlimited data as the payload to POST method.
But, if we consider a real use case,
then sending POST with large payload will 
consume more bandwidth. 
It’ll take more time and present performance
challenges to your server. Hence, 
a user should take action accordingly.