Hi Angel,
The 504 Gateway Timeout error is an HTTP status code that means that one server did not receive a timely response from another server that it was accessing while attempting to load the web page or fill another request by the browser.This means that the other server is down or not working properly.
Since it is a network error between servers on the Internet or an issue with the actual server, meaning the problem is probably not with your computer, device, or Internet connection.So you can't fix it.You can try reloading your web page or restarting all of your network devices.If still not working,then you need to wait probably.It will start working soon.
Thanks & Regards
Bidisha