MeteorJS passwordless email authentication sends a link pointing to the specific server instead of domain name

Question

I am using MeteorJS passwordless authentication, Cloudflare for DNS, Mailgun as an email server, and Nodechef for app hosting: https://docs.meteor.com/packages/accounts-passwordless

Whenever a user submits their email to receive a link in their email inbox to login to the website, the link points to the NodeChef server instead of the domain (i.e. https://example1-12820.nodechef.com instead of https://example.com). Whenever the user logs in via this link, the URL is the NodeChef server as well. I would like for the domain to be in both the link and the URL, mostly for vanity purposes.

For the following assume the correct domain should be example.com:

//body.js
import './body.html';
import { Meteor } from 'meteor/meteor';
import { Template } from 'meteor/templating';
import { Accounts } from 'meteor/accounts-base';

Template.App_body.events({
    'submit #login-form'(event) {
        event.preventDefault();
        const email = event.target.email.value;
        if (email == "") {
            FlashMessages.sendError("Must enter email to receive link");
        } else {
            Accounts.requestLoginTokenForUser({ 
                selector: email.toLowerCase().trim(),
                userData: { email: email.toLowerCase().trim() }}, function (error) {
                if (error) { 
                    FlashMessages.sendError(error); 
                } else {
                    FlashMessages.sendSuccess("Check email for login link");
                }
            });
        }
    },
});

//fixtures.js
import { Meteor } from 'meteor/meteor';
import { Accounts } from 'meteor/accounts-base';

Meteor.startup(() => {
  process.env.MAIL_URL = Meteor.settings.MAIL_URL;
  Accounts.emailTemplates.siteName = 'Example';
  Accounts.emailTemplates.from = 'Example Admin <[email protected]>';
  Accounts.emailTemplates.sendLoginToken = {
    subject() {
       return "Login to Example";
    },
    text(user, url) {
       return `Hi there! Login to Example by following this link: ${url}`;
    }
  };
});

//settings.json
{
"MAIL_URL": "smtp://[email protected]:[email protected]:587"
}

The following are the relevant Cloudflare DNS records of type, key, and value:

CNAME email.mg mailgun.org
CNAME example.com example1-12820.nodechef.com
MX mg mxa.mailgun.org
MX mg mxb.mailgun.org
TXT mg v=spf1 include:mailgun.org ~all

There are other records, but they do not seem to be related.

I have tried changing CNAME and MX records, as well as checking within Mailgun and Cloudflare and NodeChef whether there is a setting that would change the URL sent in the login link to no avail