Welcome to the Atlassian Community!
There are hundreds of thousands of installations of Jira across the world. The obvious question for the community here is "which one are you talking about"?
But that doesn't really matter, the answer from us has to be "You need to talk to the owners or admins of the Jira system you are trying to get into".
Best thing you can do if you don't know who they are is to ask the people who asked you to use the Jira you're asking about. Or other users of it.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.