missing module when deploy nodejs application to heroku - node.js

Question

When I tried to deploy my app to heroku, I kept getting this error in the log
2022-05-20T14:49:35.602605+00:00 app[web.1]: > node server.js
2022-05-20T14:49:35.602605+00:00 app[web.1]:
2022-05-20T14:49:35.719423+00:00 app[web.1]: node:internal/modules/cjs/loader:936
2022-05-20T14:49:35.719424+00:00 app[web.1]: throw err;
2022-05-20T14:49:35.719425+00:00 app[web.1]: ^
2022-05-20T14:49:35.719428+00:00 app[web.1]:
2022-05-20T14:49:35.719428+00:00 app[web.1]: Error: Cannot find module 'csv-parse'
2022-05-20T14:49:35.719428+00:00 app[web.1]: Require stack:
2022-05-20T14:49:35.719429+00:00 app[web.1]: - /app/server.js
2022-05-20T14:49:35.719430+00:00 app[web.1]: at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
2022-05-20T14:49:35.719431+00:00 app[web.1]: at Function.Module._load (node:internal/modules/cjs/loader:778:27)
2022-05-20T14:49:35.719431+00:00 app[web.1]: at Module.require (node:internal/modules/cjs/loader:1005:19)
2022-05-20T14:49:35.719431+00:00 app[web.1]: at require (node:internal/modules/cjs/helpers:102:18)
2022-05-20T14:49:35.719432+00:00 app[web.1]: at Object.<anonymous> (/app/server.js:6:15)
2022-05-20T14:49:35.719432+00:00 app[web.1]: at Module._compile (node:internal/modules/cjs/loader:1105:14)
2022-05-20T14:49:35.719432+00:00 app[web.1]: at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10)
2022-05-20T15:08:40.259973+00:00 app[web.1]: Error: Cannot find module 'express'
2022-05-20T15:08:40.259974+00:00 app[web.1]: at Function.Module._resolveFilename (module.js:536:15)
2022-05-20T15:08:40.259974+00:00 app[web.1]: at Function.Module._load (module.js:466:25)
2022-05-20T15:08:40.259974+00:00 app[web.1]: at Module.require (module.js:579:17)
2022-05-20T15:08:40.259974+00:00 app[web.1]: at require (internal/module.js:11:18)
2022-05-20T15:08:40.259975+00:00 app[web.1]: at Object.<anonymous> (/app/server.js:5:17)
2022-05-20T15:08:40.259975+00:00 app[web.1]: at Module._compile (module.js:635:30)
2022-05-20T15:08:40.259975+00:00 app[web.1]: at Object.Module._extensions..js (module.js:646:10)
2022-05-20T15:08:40.259975+00:00 app[web.1]: at Module.load (module.js:554:32)
2022-05-20T15:08:40.259976+00:00 app[web.1]: at tryModuleLoad (module.js:497:12)
I am pretty sure the node.js application can successfully run locally and I have installed all the necessary packages in dependencies inside package.json. Not sure how to fix it....
Here is my package.json
{
"name": "Netflix User Study Framework",
"version": "1.0.0",
"description": "Encode username into prolific id",
"main": "server.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1",
"start": "node server.js"
},
"engines": {
"node": "8.9.3"
},
"repository": {
"type": "git",
"url": "git+https://github.com/amyhua/basic-website-template-node.git"
},
"author": "YOUR NAME GOES HERE",
"bugs": {
"url": "https://github.com/amyhua/basic-website-template-node/issues"
},
"homepage": "https://github.com/amyhua/basic-website-template-node#readme",
"dependencies": {
"aws-sdk": "^2.1139.0",
"csv-parser": "^3.0.0",
"csv-stringify": "^6.0.5",
"express": "^4.14.0",
"generate-unique-id": "^2.0.1",
"http": "0.0.0",
"multer": "^1.4.4",
"nodemon": "^1.11.0",
"os": "^0.1.2"
}
}
Also, I set up a .env file with PORT # on 3000.