Node.js Debugging for Email Verification during login/signup process - Debugging

I need a skilled Node.js developer to debug and resolve an issue with email verification in my Android Studio app.

The front end request is being sent, and the verification code is not being received in the email. It shows in Logcat with an error: "Incorrect parameters, Status: 400".

Stack: Node.JS, MongoDB, Android Studio

Current stage:
- Front end request in JSON body sent to backend.
- All code for front end and backend login/signup is created.

Ideal Skills and Experience:
- Proficiency in Node.js and MongoDB
- Experience with Android Studio and handling JSON requests
- Strong debugging skills to resolve 400 status errors
- Familiarity with email verification workflows

Looking for someone who can quickly identify and fix the issue.