Как перейти на бесплатный тариф?

@Андрей Обухов - I hope you do not mind my reply in English.

For most paid plans, you cancel your subscription by following the instructions in the How to Cancel Your Subscription Help Center article.

A few other articles that you should review and maybe bookmark:

• What Happens When a Subscription Expires
• The Board is Locked - this can happen when moving from a paid to Free Plan