refer to this instruction
https://developer.atlassian.com/server/jira/platform/jira-rest-api-example-oauth-authentication-6291692/?_ga=2.99968795.426460616.1568534217-602959315.1566627369
There is section “Enter in this the public key and the consumer key which your client will use when making requests to JIRA. After you have entered all the information click OK and ensure OAuth authentication is enabled.”
How to get consumer key and public key or anyone has an example that mostly appreciated. !