as you know, jira is changing their authentication method, if you want to integrate your app with jira which is hosted on their own cloud you are not allowed to use old user credential like username and password and you have to use `API KEY` instead.
this is a documentation how to create API KEY for my self:
https://confluence.atlassian.com/cloud/api-tokens-938839638.html
but, let say I am creating an application an I want to integrate my application with Jira how can I find this `API KEY`? how can I generate this for user in backend?