Hello,
I have gone through your requirements, you are facing issue with payment gateway in your existing android app.
So, Yes I am ready to fix it.
I have experience of payment gateway like Payumoney, Molpay, Paypal. & as I have a vast experience in android development it will be easy for me to understand your code & fix things.
I can start work on it now.
Let me tell you about myself, I am fresher on this platform but I have worked on more than 40 android applications in four and half years of my professional career.
I have expertise in android development, full knowledge of Android life cycle - Material design - REST api - Sqlite database - Payment integration - Third party library integration - Background services - Firebase.
One more thing I am full time freelancer so will always available for support and communication.
Let me know if you are interested, I am ready to discuss everything before you award me this task.
Thanks,
Hardip