How to access another docker container from one docker container?

Question

System administration

Hello!
There are 2 separate projects locally deployed on the PC:
- frontend - where docker-compose consists of a single node-container;
- backend - there docker-compose consists of 3 containers (we will be interested only in nginx on port 88) ;
As I understand it, each project (docker-compose.yml) eventually creates its own network (network) - in the picture below I have shown how it looks (if I understand everything correctly).
What is the problem:
1. From the browser I knock on localhost:3000
2. The request successfully reaches node.js (I see it in the logs)
3. Next, node.js pulls the container with the API - it accesses http://172.18.160.225:88 *
4. ... and on this request falls off by timeout.
* - if I access this address from the browser - there will be no timeout.
As a result, it turns out that I have 2 neighboring docker networks deployed locally, and from one I cannot reach the second. But the task seems to be trivial.
People who know, tell me, please, what is the problem and how to solve this problem?

Answer 1

Specify a specific network for containers via networks:
and contact not via ip but via the name nginx:88 or whatever it is called
https://docs.docker.com/compose/networking/

Answer 2

Wouldn't it be easier to combine the backend and frontend in one docker-compose?