Rest api cors issue

I have created an app in IONIC using Cuba rest js which is getting data from CUBA application hosted on web. My ts file is like this

import { Component } from '@angular/core';
import * as cuba from '@cuba-platform/rest';
@Component({
  selector: 'app-home',
  templateUrl: 'home.page.html',
  styleUrls: ['home.page.scss'],
})

export class HomePage  {
  myApp:cuba.CubaApp;
  loginResult:string;
  constructor() {
    this.loginResult = "Initialised";
  }

  ionViewWillEnter(){
    const app = cuba.initializeApp({
      name: 'myApp',
      apiUrl: 'http://xxxxxx.cloudjiffy.net/app/rest/',
      restClientId: 'xxxxxxxx',
      restClientSecret: 'xxxxxx'
    });
    this.myApp = cuba.getApp('myApp');
  }

  login(){
    this.myApp.login('xxxxxxx','xxxxxxxxx').then(value =>{
      this.loginResult = "Succesful";
    })
    .catch(ss=>{
      this.loginResult = ss;
    })
  }
}

Though the application run smoothly with cuba application on local host, but with cuba application on web, it gives a CORS error.
IONIC app running on browser

Access to fetch at ‘http://tmphed.cloudjiffy.net/app/rest/v2/oauth/token’ from origin ‘http://localhost:8100’ has been blocked by CORS policy: Response to preflight request doesn’t pass access control check: No ‘Access-Control-Allow-Origin’ header is present on the requested resource. If an opaque response serves your needs, set the request’s mode to ‘no-cors’ to fetch the resource with CORS disabled.

IONIC App running on mobile

CubaRestError: Failed to Fetch

I have tried org.apache.catalina.filters.CorsFilter CORS filters in TOMCAT web.xml file in webapps folder but no avail. There are large number of posts on stackoverflow saying that Catalina CORS filter in not working on TOMCAT and tried the solutions mentioned in these posts but not successfull.
CUBA documentation says by default, all CORS requests to the REST API are allowed.
Please guide
regards

If CUBA application didn’t allow CORS requests, it wouldn’t work at localhost as well. If it works fine at localhost:8080, then it’s probably not CUBA application settings that forbid CORS requests.
I didn’t have experience in working with cloudjiffy. Did you try deploying your CUBA app to some other PaaS (not cloudjiffy)? Do you get the same CORS errors if you deploy somewhere else?

Thanks Maxim. But even jmix documentation says it support CORS by default. Please elaborate in light of your post on jmix https://forum.jmix.io/t/cors-problem-with-authenticatedurlpatterns/1172 wherein you have recommended to specify CORS configuration for your URLs explicitly.
I am calling rest api through URLs like this
‘’’
http://localhost:8080/app/rest/v2/oauth/token
http://localhost:8080/app/rest/v2/entities/sales$Order
‘’’
I have already applied CORS filter in TOMCAT. Pl guide.
Thanks

Jmix documentation says that CORS requests to standard REST API endpoints (like /rest/**) are allowed by default. All other endpoints are not allowed, you must define additional configuration for them - that’s what the post you reference was about.