Blitz.JS をHerokuにデプロイ時にRelease phase error

Question

Blitz.JS でアプリを作成後、Blitz.JS 公式サイトの手順に従いHerokuにデプロイしようとしたところ、Release phase時に
Error: Cannot find module 'prisma'　Require stack:- /app/noop.js　Code: MODULE_NOT_FOUND
というエラーが発生。

{
  "name": "blitz",
  "version": "1.0.0",
  "scripts": {
    "dev": "blitz dev",
    "build": "blitz build",
    "start:production": "blitz start --port $PORT",
    "studio": "blitz prisma studio",
    "lint": "eslint --ignore-path .gitignore --ext .js,.ts,.tsx .",
    "test": "jest",
    "test:watch": "jest --watch"
  },
  "prisma": {
    "schema": "db/schema.prisma"
  },
  "prettier": {
    "semi": false,
    "printWidth": 100
  },
  "lint-staged": {
    "*.{js,ts,tsx}": [
      "eslint --fix"
    ]
  },
  "dependencies": {
    "@fortawesome/fontawesome-svg-core": "1.2.35",
    "@fortawesome/free-solid-svg-icons": "5.15.3",
    "@fortawesome/react-fontawesome": "0.1.14",
    "@prisma/client": "2.26.0",
    "@tailwindcss/line-clamp": "0.2.1",
    "axios": "0.21.1",
    "blitz": "0.38.2",
    "final-form": "4.20.2",
    "passport-github": "1.1.0",
    "passport-google-oauth2": "0.2.0",
    "react": "alpha",
    "react-dom": "alpha",
    "react-final-form": "6.5.3",
    "react-intersection-observer": "8.32.0",
    "react-loading": "2.0.3",
    "react-transition-group": "4.4.2",
    "recoil": "0.3.1",
    "xmljson": "0.2.0",
    "zod": "3.3.4"
  },
  "devDependencies": {
    "@types/preview-email": "2.0.0",
    "@types/react": "17.0.13",
    "autoprefixer": "10.2.6",
    "eslint": "7.30.0",
    "husky": "6.0.0",
    "lint-staged": "10.5.4",
    "prettier": "2.3.2",
    "prettier-plugin-prisma": "0.13.2",
    "pretty-quick": "3.1.1",
    "preview-email": "3.0.4",
    "prisma": "2.26.0",
    "tailwindcss": "2.2.4",
    "typescript": "~4.3"
  },
  "private": true
}

release: npx blitz prisma migrate deploy
web: npm run start:production

＜試したこと＞
prismaがインストールされているか確認した。

<参考サイト>
https://blitzjs.com/docs/deploy-heroku

よろしくお願いします。