Guide on how to carry out a successful transaction on react native

I am using paypack to build a react native app. Was wondering how I can send a provide a way for users to input their otp. My response is always ‘pending’ then ‘failed’. From the documentation, I have sent a post request to cashin with all the required parameters. What next do I have to do to ensure a successful transaction. Thank you.

Can you share with me your transaction ref?

5460ab2e-c994-4fe0-925e-3cb023ce2279

Did the user finalize the payment process?