Module not found: Error: Can’t resolve ‘@babel/runtime/helpers/createClass’

I am importing an external package into a CyberChef custom operation. I am not sure how I should import the package. The package is not published but is link using a file:./... dependency.

From CyberChef

MyOperation.mjs

import SystemDatabase from "test-db";

My external package

package.json

{
    "name": "test-db",
    ...
    "main": "src/main.js",
    ...
}

main.js

import SystemDatabase from "./SystemDatabase.js";

module.exports = {
    SystemDatabase
};

SystemDatabase.js

class SystemDatabase {
// ...
}

module.exports = {
    SystemDatabase
};

Build error

This is the error I don’t understand.

ERROR in ../[REDACTED]/test-db/src/SystemDatabase.js 2:0-62
    Module not found: Error: Can't resolve '@babel/runtime/helpers/createClass' in '[REDACTED]/test-db/src'
    resolve '@babel/runtime/helpers/createClass' in '[REDACTED]/test-db/src'
      Parsed request is a module
      using description file: [REDACTED]/test-db/package.json (relative path: ./src)


        Field 'browser' doesn't contain a valid alias configuration
        resolve as module
          [REDACTED]/test-db/src/node_modules doesn't exist or is not a directory
          [REDACTED]/test-db/node_modules doesn't exist or is not a directory
          [REACTED]/node_modules doesn't exist or is not a directory
          ...
     @ ../[REACTED]/test-db/src/main.js 2:0-47 4:2-15
     @ ./src/core/operations/MyOperation.mjs 15:0-44
     @ ./src/core/config/modules/MyModule.mjs 12:0-69 22:18-34

Follow-up

After installing babel-runtime to my external package. I now get the runtime error:

ES Modules may not assign module.exports or exports.*, Use ESM export syntax

If I use export default syntax, I get :

SyntaxError: Cannot use import statement outside a module

I want my package to import in all JS project types.