To activate your website or funnel to be publicly visible you need to subscribe to one of the premium plans. To do that just click on the Upgrade Now button on the bottom of the platform:
You will be redirected to the Billing section to select a premium plan.
Choose a plan based on the resources you need. The system knows what resources you are currently using and will prompt you choose a different plan if the one you select doesn't include the features you are using.
Press select on your desired plan. In the following page, all you need to do is add your billing details and click on the "Subscribe" button to complete your purchase and activate your website or funnels.