A quick Android App Fix

One of my android app stopped working after server upgrades sometime ago did not notice. The app is very basic app to display few products and generate query for admin. The app just keeps loading on after splash screen is gone. I can access the APIs they are working but I found error for authentication probably. I just need to check what error is coming so then I can update settings on server. Its built on native android in java. Anyone can fix me my system is crashed and I am unable to run android for testing on this old machine. So I need someone to fix my issue to trace where it got stuck which will not take long I will supply android app code APIs access and any information if required to proceed the work. I am looking for long term Native app developer for my upcoming projects and current work updates. Budget is very low for this as only require test and deploy again ( I can publish as well ) just in case. App reference in chat.