Can't login at home

[Jack]

I can use my email address let's say jack@company.com to login to JIRA in office, all work well.

Then I go back home, try to login JIRA using the same email jack@company.com and password with the same url.

But it says:

Did you use the wrong account?

Your email address jack@company.com doesn't have access to company.atlassian.net

We've all got more than one email address these days - are you using the right one?

If you're certain you should have access with jack@company.com, contact your administrator.

How?

[Jack]

then I type the URL of a specific issue, I can view it. means I've already login.

although what the login page says otherwise