How to make a rest call to create ticket in external system from JIRA

[Sugandha]

Hi. I need to make a REST call to another application from JIRA.

I have a json to create a ticket in another system.

So once I create a jira ticket, i want a post-function should execute that should create a ticket in external system

I have a json body but dont know how to  write a groovy script that will create ticket.