Hi @sheeshwho!
To request a customer to rate the conversation over email after closing a Conversation/ticket, you can enable email notifications for ticket status updates. When a Conversation or ticket reply hasn't been seen by a user after 3 minutes, an email notification can be sent.
To enable these notifications, you can go to Settings > Channels > Email and under Email notifications. For more information on how customers get notified via email, check out our Help Center - Push, email, chat and post notifications for customers
You can also use the Teammate changes the conversation state Workflow trigger to send the CSAT survey to customers.