How to create a load test with variable JSON

I have a REST API to test where I create user accounts. I need to test the performance in the server when there is a huge amount of user creation requests arrive. What I do is, I POST a json to a specific URL. The username needs to be changed for every user.

Next once the user is created I need to use the Id from returning response to add more information to the just created user.

Is this kind of behavior can be simulated by Load? if yes, how