How to send data that will come from TCP without blocking the stream?

Question

Node.js

The client sends a request to the nodejs http server.
Nodejs HTTP Server sends a request to TCP and waits for a response.
The TCP client sends a response and needs to be returned back to HTTP.
There is a wait in http here, but the wait is blocking the stream. How can I make it so that the thread is not blocked, but the timeout remains? What to use for this?