java.io.EOFException: null while running Postgres via docker-compose

I'm new to docker-compose, wanted to run a container with Postgres db in it. For this I've created a docker-compose.yml with the following content:

services:
  postgresql:
    image: postgres
    container_name: postgres_db
    ports:
      - "5433:5433"
    environment:
      - POSTGRES_PASSWORD=admin
      - POSTGRES_USER=postgres
      - POSTGRES_DB=testdb

So far I didn't pack my Spring Boot app in a container as well, as I'd like to do it step by step and for now run only the database in container.

I start it with docker-compose -f docker-compose.yml up, then I run my app in Intellij and see that in logs:

org.postgresql.util.PSQLException: The connection attempt failed. Caused by: java.io.EOFException: null

Via docker-exec I was able to connect to my testdb. However, in Intellij I can't do the same via Database tool, I keep getting authentication error (username/password are wrong).

I'm struggling with these new concepts. What am I missing here?