You may see a security warning when you visit you newsroom within 5 minutes of its creation:
You don't have to worry about it. It's just because Pressbase is in the process of creating the SSL certificate for your newsroom. In most cases, it should be completed within 5 minutes. And it's a one time process.
After a few minutes of its creation, the warning should disappear when you visit your newsroom again.
If you cannot wait to visit your Newsroom admin, you can access it via the pressbase.io URL. You can find the URL on this page: https://pressbase.io/newsrooms.
You just need to append /admin at the end of the pressbase.io URL to visit the newsroom admin. For example, if you pressbase.io URL is https://xxxxx.pressbase.io, then your alternative newsroom admin URL is https://xxxxx.pressbase.io/admin.