Sorry for the confusion. Closing the topic won’t automatically redirect users to the new topic. What it does is prevent further replies to the old topic.
The suggestion was to manually add a note to the closed topic, providing a link to the new topic. This way, anyone who visits the old topic will see the note and can follow the link to the new topic.
Here’s an example of what you might write in /t/test/1234:
“This topic is now closed. Please continue the discussion here - https://mydomain.com/t/test2/5678.”