Generating JWT.

createToken.js

const jwt = require('jsonwebtoken');
const fs = require('fs');

// Get jwt.dev.key from AWS Secrets Manager.
const privateKey = fs.readFileSync('jwt.dev.key');

const payload = {
  user: {
    // Must correspond with the ID of a user, in whichever database your connecting to.
    // Otherwise, inserts will fail, due to FK constraints.
    id: 'your-id',
    username: 'FPL_YourUsername',
    // Optionally also include is_admin: true, if you want greater access
  },
  session: {
    id: 'some-session-id', // Not really important.
  },
  // Must be a user token.
  // This is a flag that may be used in the future, e.g. for some other token types.
  token_type: 'user',
};

const options = {
  algorithm: 'RS512',
  noTimestamp: true,
  // Specify however long you wish to keep this token valid.
  // These are usually only valid for 15 minutes.
  // Maybe a year is overkill, eh?
  expiresIn: '1 year',
};

const token = jwt.sign(payload, privateKey, options);

console.log(token);