# Frequently Asked Questions
Find answers to common questions about the API, integration, and troubleshooting.
# What should I do if I receive a 400 Bad Request error?
Check that all required fields are present and valid. Common causes include:
- Missing or invalid enum values
- Incorrect data types
- Required fields left empty
Refer to the API reference for field requirements.
# How can I test the API in a sandbox environment?
Contact your Netomnia account manager to request sandbox access and credentials. Use the provided base URL for all test requests.
# Who do I contact for support?
See the General Support page for support contact details and escalation procedures.