In Jmeter, What would be syntax of parameters in Body Data section of HTTP Request Sampler, if I am using Rest APIs and taking input from CSV files?

I am trying to create 10 users at the same time in Jmeter, using REST APIs. Test Data i.e. input is taken from CSV files (The details of users like user name, last name , mobile) For this I have added one thread group,User Defined Variable,HTTP Header Manager, HTTP Request Sampler (which perform successful login into web application), JSON PATH EXTRACTOR ( to extract auth token, which will be used

[snjx]

Body Dataに、普通に変数が使える。