{{community_id}} - Your unique community identifier{{WIDGET_API_KEY}} - Your secret API key for authentication{{WIDGET_API_KEY}} secret! Never expose it in frontend code or commit it to public repositories.{{widget_ID}} - The specific widget instance identifierYour Frontend → Your Backend → Returning.AI API → Token → Widget{{WIDGET_API_KEY}} would be exposed in the browserPOST https://prod-widgets.returning.ai/widget/{{community_id}}/signinreturningai-api-key: Your Widget API Key (from admin panel)email: The logged-in user's email from your auth systemContent-Type: application/json{{widget_type}}: The type of widget (see supported features below){{widget_ID}} : Your specific widget ID from the admin panelcommunity_id, widget_type and widget_ID are correctWIDGET_API_KEY is correct and stored securely in environment variablesevent.origin matches exactly: https://prod-widgets.returning.aievent.origincommunity_id, WIDGET_API_KEY, and widget_ID from admin panel