Once a chat is finished, a transcript is generated, containing all messages from a single chat. The transcript will be created in the customer's language, meaning it will contain the original message from the customer and the translated version from the agent. You can access a chat transcript from the History tab, as described in this Zendesk article.
Additionally, if the option to automatically create a ticket when a chat is started is selected, or if a ticket is created manually since then, Zendesk will post a chat transcript as a comment on that ticket, along with other relevant information, such as Chat ID, agent that served the chat, etc. The ticket can be accessed from the Chat transcript view under the History tab.
This transcript differs from the Unbabel transcript, which you can read more about here.