-App Login Problem

When you open the app, first it's a red screen, then comes which color screen?
You can take a screenshot of your login page.
 
Black screen means unable to connect to our server due to network problem.
There are many reasons for network problems, whether the app has got network access, whether the local router has set up some kind of firewall rules, whether the local isp has blocked the ip segment of our website, all of which may lead to inaccessibility.
You need to check them one by one.