You can't publish in journals or other publications while on a free trial. However, you can end your free trial early if you need to do so.
To end your free trial early:
Click your name in the top-right corner, then click Account.
Click Plan & Billing.
Under Your Plan, you’ll see a grey box outlining publishing rights and icon requests. Click start plan now.
When the pop-up appears, click Start plan now.
Now you may publish in journals and for other academic purposes. To learn more, click Learn more about publishing rights.