Mixed Content: The page was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint

It’s from the index route and It’s using ember-data:

import Ember from 'ember';
import formatMoney from "accounting/format-money"

export default Ember.Route.extend({
  model() {
    return this.get('store').findAll('contrato');
  },

  setupController(controller, model) {
    this._super(controller, model);
    this.get('store').findAll('contrato').then((contratos) => {
      let total = contratos.reduce((a, b) => {
        return a + b.get("value");
      }, 0);
      this.controllerFor('index').set('totalSum', formatMoney(total, "R$", 2, ".", ","));
    });
  },

});

It’s really weird and I’m still lost trying to solve it. Does it have something to do with nginx? Here’s the nginx.conf file:

user nginx;
worker_processes 1;

error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events
{
  worker_connections 1024;
}

http
{
  include /etc/nginx/mime.types;
  default_type application/octet-stream;
  sendfile on;
  access_log /var/log/nginx/access.log;
  keepalive_timeout 3000;
  server
  {
    listen 80;
    root /app;
    client_max_body_size 32m;

    location /
    {
      try_files $uri /index.html;
    }
  }
}