Flyway not connecting to postgresql

I have a problem for a time and I yet have to find out why it is happening.

I'm trying to build a "instagram clone" to study Golang, but I cannot find out why my flyway does not connect to my postgresql.

Here is my docker compose:

version: "3.8"

services:
  server:
    build: .
    ports:
      - "3000:3000"
    volumes:
      - .:/usr/src/app
  db:
    image: postgres:14.5
    environment:
      POSTGRES_DB: instagram
      POSTGRES_USER: instagram
      POSTGRES_PASSWORD: instagram
    ports:
      - "5432:5432"
  flyway:
    image: flyway/flyway:9.9.0
    entrypoint:
      - sh
      - -c
      - flyway -defaultSchema=public -baselineOnMigrate=true -url=jdbc:postgresql://localhost:5432/instagram -user=instagram -password=instagram migrate
    depends_on:
      - db
    volumes:
      - ./data/sql:/flyway/sql

The database seems to be correctly created, I can access it through DBeaver, however, my flyway cannot connect to it.

I'm running it on a WSL2, I have already clear my docker deleting every container, volume and image from it once or twice. I'm running it with docker compose up db followed by docker compose up flyway. Does anyone have any ideas?

EDIT: This is my docker compose file after the resolution for anyone that may need it

version: "3.8"

services:
  server:
    build: .
    ports:
      - "3000:3000"
    volumes:
      - .:/usr/src/app
  db:
    image: postgres:14.5
    env_file:
      - ".env"
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U instagram"]
      interval: 10s
      retries: 5
    ports:
      - "5432:5432"
  flyway:
    image: flyway/flyway:9.9.0
    entrypoint:
      - sh
      - -c
      - flyway -defaultSchema=public -baselineOnMigrate=true -connectRetries=60 -url=jdbc:postgresql://db:5432/instagram -user=instagram -password=instagram migrate
    depends_on:
      - db
    volumes:
      - ./data/sql:/flyway/sql

Sometimes DB container takes a few seconds to spin up. Use -connectRetries=60 flag in the command for automatic retries every second for x seconds. Check GitHub Flyway docker

Using health check:

healthcheck:
  test: ["CMD-SHELL", "pg_isready -U instagram -d instagram -h db"]
  interval: 5s
  timeout: 5s
  retries: 10

Also, you can try to wait in an infinite loop in the command:

flyway:
  image: flyway/flyway:9.9.0
  command: ["sh", "-c", "while ! nc -z db 5432; do sleep 1; done; flyway -defaultSchema=public -baselineOnMigrate=true -url=jdbc:postgresql://db:5432/instagram -user=instagram -password=instagram migrate"]
  depends_on:
    - db
  healthcheck:
    test: ["CMD-SHELL", "pg_isready -U instagram -d instagram -h db"]
    interval: 5s
    timeout: 5s
    retries: 10
  volumes:
    - ./data/sql:/flyway/sql