In Odoo, we can use preconfigured templates to send a message to the customer after 24 hours. With the following guide, you'll learn how to set up a template to "revive" a closed conversation.
English Version:
https://docs.google.com/document/d/1wXZp3XTDULSVQDJ1c_fdu3GPXOH8kKWRoXKuyIjOZWo/edit?usp=sharing
Spanish Version:
https://docs.google.com/document/d/1YaPnAFJ31NBCoD7Nf0g7JOm1T6bagwe_mLCSQEUm7yI/edit?usp=sharing