Migrate command not found on release

Questions / Help
1

I’ve got an umbrella app, when I run deploy, I get

	 Preparing to run: `launcher eval DertGGWeb.Release.migrate` as heroku
	 2022/06/17 22:04:00 listening on [fdaa:0:6e5f:a7b:67:4c1f:fd90:2]:22 (DNS: [fdaa::3]:53)
	 eval: DertGGWeb.Release.migrate: command not found

I’ve already got the DertGGWeb.Release module in the correct place.

fly.toml

# fly.toml file generated for broken-rain-627 on 2022-06-16T22:12:45+02:00

app = "broken-rain-627"

kill_signal = "SIGINT"
kill_timeout = 5
processes = []

[build]
  builder = "heroku/buildpacks:20"
  buildpacks = ["https://cnb-shim.herokuapp.com/v1/hashnuke/elixir"]

[env]
  PORT = "8080"

[experimental]
  allowed_public_ports = []
  auto_rollback = true

[[services]]
  http_checks = []
  internal_port = 8080
  processes = ["app"]
  protocol = "tcp"
  script_checks = []

  [services.concurrency]
    hard_limit = 25
    soft_limit = 20
    type = "connections"

  [[services.ports]]
    force_https = true
    handlers = ["http"]
    port = 80

  [[services.ports]]
    handlers = ["tls", "http"]
    port = 443

  [[services.tcp_checks]]
    grace_period = "1s"
    interval = "15s"
    restart_limit = 0
    timeout = "2s"

[deploy]
  release_command =  "eval DertGGWeb.Release.migrate"

runtime.exs

import Config

if config_env() == :prod do
  database_url =
    System.get_env("DATABASE_URL") ||
      raise """
      environment variable DATABASE_URL is missing.
      For example: ecto://USER:PASS@HOST/DATABASE
      """

  # maybe_ipv6 = if System.get_env("ECTO_IPV6"), do: [:inet6], else: []

  config :dert_gg, DertGG.Repo,
    ssl: false,
    url: database_url,
    pool_size: String.to_integer(System.get_env("POOL_SIZE") || "10"),
    socket_options: [:inet6]

  secret_key_base =
    System.get_env("SECRET_KEY_BASE") ||
      raise """
      environment variable SECRET_KEY_BASE is missing.
      You can generate one by calling: mix phx.gen.secret
      """

  config :dert_gg_web, DertGGWeb.Endpoint,
    http: [
      # Enable IPv6 and bind on all interfaces.
      # Set it to  {0, 0, 0, 0, 0, 0, 0, 1} for local network only access.
      ip: {0, 0, 0, 0, 0, 0, 0, 0},
      port: String.to_integer(System.get_env("PORT") || "4000")
    ],
    secret_key_base: secret_key_base,
    server: true
end