XMLHttpRequest on the main thread

Is there any way to get rid of the warning in chrome that says:

"Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user’s experience. For more help, check https://xhr.spec.whatwg.org/."?

If you use the asynchronous version of the API, the warning should not appear.

Ok. Right now, I’m referencing //api.backendless.com/sdk/js/latest/backendless.min.js

Where is the asynchronous version located?

In the same JS. Every API has sync and async version. It is documented here:

https://backendless.com/documentation/users/js/users_sync_and_async_api.htm