Integration with SolanaPay and NextJS: Integrating different technologies and frameworks is always challenging, especially when dealing with complex APIs and libraries. To overcome this, we carefully reviewed the documentation, took help from online communities and forums, and debugged the code using tools such as console logs and error messages.

Wallet connectivity and transaction errors: When working with cryptocurrency wallets and payment gateways, we encountered errors related to connectivity, authentication, and transaction processing. To address this, we tested the code on different devices and networks, ensure that the wallets are properly configured, and handle errors gracefully in the code.

Security and data privacy: Building a payment app that handles sensitive financial information requires careful attention to security and data privacy. We had to implement robust authentication and encryption measures, follow industry best practices for secure coding and deployment, and comply with relevant data protection laws and regulations.