Flask API POST Error Debugging

I'm encountering a 404 Not Found error in my Flask and HTML project when making a POST request to an API endpoint. This issue needs urgent attention and must be resolved by this Sunday. Key Details: - The error occurs during a POST request at an API endpoint. - The specific error message is "Save mapping error" - The issue is time-sensitive, requiring resolution by Sunday. Ideal Skills and Experience: - Proficient in Flask and HTML - Experience in debugging API-related issues - Ability to resolve issues under time pressure