Azure Open AI needs extra fields:

• Azure OpenAI Endpoint (Your Azure OpenAI resource endpoint URL), $endpoint below.
• Azure API Version (e.g., 2024-02-15-preview), $api_version below.
• (Model must be one of the models you've added to your Azure Open AI resource, $model below.)

// Azure OpenAI endpoint format
$url = rtrim( $endpoint, '/' ) . '/openai/deployments/' . $model . '/chat/completions?api-version=' . $api_version;