Official Documentation
https://confluence.atlassian.com/cloud/api-tokens-938839638.html
CREATE API TOKEN
Go to your Atlassian Profile i.e. https://id.atlassian.com/manage-profile
Go to Security Tab and Click Create and manage API tokens
Click Create API Token
USE BELOW FOR OKTA GROUP SYNC
email@example.com:apitoken
e.g. hello.world@example.com:934ur3r034jf043ee
Please make sure above API user has Jira global permission to Browse Users and Groups. i.e.
Go to Jira Settings > System > Global Permissions > Browse Users and groups