Creating a new request via URL

Creating a new request via URL

I am trying to create a new request and pass data to it while using this. I am unsure what the proper formatting of the url. to start what would our URL be to creat a new request without data then what would it be to pass the data through? something like

new blank request: https://helpdesk.{instance}.com/api/v3/request
passing data: https://helpdesk.{instance}.com/api/v3/request?subject=test

my problem is the first one just pulls request data and the second one tells me I have extra parameters