There are two ways to move to another pricing plan of the PostTrack:
1. Go to the page "Details" at the PostTrack Office extension control panel (https://posttrack.email/office/details) and press the appropriate button. These buttons can be of two types: "Upgrade" - allows you to change your plan to better one, and "Downgrade" - allows you to change you plan to cheaper one. After pressing on one of buttons you will be redirected to the payment page of the plan you will move on. Note, that it is impossible to move from any chargeable plan to the "Trial" plan.
2. If you are logged in, you can go to the "Pricing" page (https://posttrack.email/ru/pricing) and choose one of the available for you pricing plans.