You can utilize the live chat window of United Airlines to request a callback. Follow the given steps to have a conversation with a customer service representative regarding the callback:
Reach united.com
Go to the customer contact detail page
Click on ‘chat with us.’
Enter your callback request
Send the message
Mention your desired time and date for the callback
The customer service person will confirm your request immediately.
You can also make a callback request from the United airlines phone app. Download the app on your mobile and request through the app.
Therefore to learn How do I get a callback on United Airlines?, please refer to the above ways to receive a call from United Airlines.