To manage the tariff of your chats, click on the "Settings" button to open the menu. In this menu, you can choose the rate for your private chat (5, 7, or 10 credits per minute) and your VIP chat (10, 15, or 20 credits per minute).
You can only modify your tariff if no client is currently connected to that type of chat. Example: If a client has requested a VIP chat, you cannot change the tariff until the VIP chat has ended.
Please note that not all models can select the 7 or 10 credits tariff for private chat. Read more about this HERE.