如何使用curl在watson助手中传递api密钥和助手url而不是用户名和密码

I want to pass apikey and url instead of username and password, to connect watson assistant with my webpage.

// Encode json data
    $json = json_encode($data, JSON_UNESCAPED_UNICODE);

    // Post the json to Watson Assistant API via cURL
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_URL, 'https://gateway.watsonplatform.net/assistant/api/v1/workspaces/'.$workspace_id.'/message?version='.$release_date); // 
    curl_setopt($ch, CURLOPT_USERPWD, $username.":".$password); // Set cURL Watson 
    curl_setopt($ch, CURLOPT_POST, true );
    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json')); 
    curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
    $result = trim(curl_exec($ch)); 
    curl_close($ch); // Close
    echo json_encode($result, JSON_UNESCAPED_UNICODE); // Send response
  }

Here i would like to replace username and password with corresponded Apikey and url .

Please try this. Instead of username, use the keyword "apikey" and for password use the actual API Key that you have for the service. That should work.