Fix Razorpay & OTP API Issues

I'm seeking a skilled developer to resolve two API integration issues:

Razorpay API:
- Currently facing authentication errors.
- API keys and credentials have been verified as correct.

2factor.com OTP API:
- OTPs are not being sent.
- API keys and credentials have been verified as correct.

Ideal Skills & Experience:
- Strong expertise in API integrations, especially with payment gateways
- Experience with 2factor.com or similar OTP services
- Ability to troubleshoot authentication errors and connectivity issues

Please provide a brief outline of your approach and relevant experience. Thank you!