How to make testcase loop/incrementally add number add the back when create username

Hi All,

Im still new with SoapUI.

Im trying to loop the testcase using soap ui. I want to have a name given to add number add the back incrementally.

Let say I have Rest POST request with

{
"userName": "${#TestSuite#userName}",
"password":"${#TestSuite#encryptedPassword}",
"firstName": "${#TestSuite#firstName}",
"lastName": "${#TestSuite#lastName}"
}

I already set the custom properties for userName and it successfully created.

I wonder how can I make it run and create user with userName1, userName2,userName3.......userName30.

Thanks