Once the trial period is over, your team plan will be switched to "Free" and you will not be invoiced automatically. If the team is over the limit allowed by the "Free" plan, export, API, CLI, and SDK functionality will become unavailable until the subscription is upgraded. If the team is over the allowed limit, the following notification message will appear:
Click the allowance exceeded link to see what exactly is over the limit.
You can find the actual pricing here.
Alternative way to subscribe
Click on your avatar and choose a team.
Click Team settings.
Open the Billing tab and press Change current plan.
Choose the plan that suits you, enter billing details, and click Subscribe.