node.js – “Error: Cannot find module ‘aws-sdk’\nRequire stack:\n- /var/task/index.js\n- /var/runtime/index.mjs” despite me adding a dependency to the sdk

I have upgraded my nodejs runtime on my lamdba function today from 10x (very outdated I realise) to 18x and I am getting the following error:

“Error: Cannot find module ‘aws-sdk’\nRequire stack:\n- /var/task/index.js\n- /var/runtime/index.mjs”

I understand that any version above 16x has to include the SDK as a dependency which I have done as part of the package.json file below:

{
  "name": "service-now-api",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "zip": "zip ../service-now-api.zip -r ."
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@aws-sdk/client-s3": "^3.216.0",
    "@aws-sdk/s3-request-presigner": "^3.216.0"
  }
}

I must be missing something I’m just not sure what, any help would be greatly appreciated

This Lambda is responsible for handling calls into a ServiceNow instance and so if the lambda fails the calls don’t get through

Below is the code from the index.js which is relevant to the aws sdk:

const https = require('https');
const AWS = require('aws-sdk');

const proxy = require('proxy-agent');

AWS.config.update({
    region: process.env.AWS_REGION,
    httpOptions: {
        agent: proxy(process.env.PROXY_URL),
    },
});