Assuming no active conversation in place, if you want to send a message to your users within a customer care session, you can send non-templated messages. The delivery of the first message will start a new service conversation (referred to as a user-initiated conversation prior to June 1, 2023), and you will be billed accordingly.
Sending template messages
As of June 1, 2023, the business-initiated conversation category has been split into three new categories (each with their own template types and pricing structure): utility, authentication, and marketing conversations. If you send a template message, and an existing conversation in the template message's category does not already exist, a new conversation will start. If you send a template message while there is already a conversation in progress, and the category of the template and the category of the open conversation do not match, a new conversation will begin in the category of the template. Finally, any template messages sent during a service conversation will begin a new conversation in the category associated with the template.