Had this exact problem six months ago when I started with Airtable’s API. Your request structure’s wrong, but there’s something others missed - you’re using the old authentication method. The api_key parameter in URLs is deprecated now. You need Bearer token authentication in headers instead. Strip the api_key from your URL completely: https://api.airtable.com/v0/appXYZ123/Students. Then add proper headers with your API key as a Bearer token. Double-check your field names match Airtable exactly - I once spent hours debugging because of a single space character difference. Fix the authentication headers and JSON formatting and your validation error should disappear.