trying to connect to gmail api using a service account on nodejs

It is my first time using the gmail api. I am trying to use the gmail api via a service account. The goal of my program is to parse emails through my email only and to look for certain keywords and compare them to a local database. However I am unable to connect to the gmail api. I did do the steps of creating the service account, downloading the service account key json file and giving permission to domain wide delegation to the service account. I have also given the scope of https://mail.google.com/. I am simply trying to prove I can connect and the authentication works by doing a getprofile call.

const {google} = require('googleapis');

const auth = new google.auth.GoogleAuth({
  keyFile: './serviceaccountkey.json',
  scopes: ['https://mail.google.com/'],
  subject: 'admin@example.org',
});


const gmail1 = google.gmail({version: 'v1', auth: auth});


async function temp1(){

  var cont = gmail1.users.getProfile({userId: "me",}) 
  return cont;
}

console.log(temp1());

This does not work as I return an error of precondition check failed.

           throw new common_1.GaxiosError(`Request failed with status code ${translatedResponse.status}`, opts, translatedResponse);
                      ^

GaxiosError: Precondition check failed.
    at Gaxios._request (C:\Users\user\Documents\FunctionAzure\node_modules\gaxios\build\src\gaxios.js:130:23)

the only code I get is 400 with message of precondition check failed.

I was expecting to see output for the get profile gmail api call. I have done some reading and my only guess is I need to do something with JWTs which I am confused about. Are JWTs and service account json file you download the same thing? I appreciate any insight anyone can offer, thank you

Based on how you're authenticating, I think you should directly request the gmail submodule which exposes 'auth' i.e. your code should be

// request the gmail module which exposes auth
const gmail = require('@googleapis/gmail') 

// provide information for authenticating
const auth = new gmail.auth.GoogleAuth({
  keyFile: './serviceaccountkey.json',
  scopes: ['https://mail.google.com/'],
  subject: 'admin@example.org',
});

// create an auth client
const authClient = await auth.getClient();

// authenticate to gmail and create a gmail client
const gmail1 = await gmail.gmail({
    version: 'v1',
    auth: authClient
});

See the example in their documentation here (look for the section - Alternatively, you can make calls directly to the APIs by installing a submodule)