There are plenty of tips and tricks available to unlock your iPhone x without using a passcode. however, before sharing some of them I would first suggest that you contact the apple support team to get assistance so that you do not lose any data from your iPhone X.
There shortest and the easiest method, performing a recovery mode on your iPhone x. This will remove the passcode from the device but it will also remove all the data that is stored on your iPhone X. Connect your iPhone to your computer and open iTunes software. Force shutdown your iPhone by pressing together the volume down key and the wake button. Keep pressing it till you get the iPhone recovery menu. On the options menu, you will get update the phone or restore the phone. Select on restore and your iPhone will begin the recovery process and delete all the data from your phone.
Another method on how to unlock iPhone X without passcode is by using a third party software. You can use iMyFone umate software. It is a very simple to use software. Connect your iPhone to your computer and launch the software. The software will automatically detect your iPhone x and once that is done, click on Erase to erase all data from the iPhone X.
You can also unlock your iPhone x without using a passcode using siri. It is basically disabling Siri and hacking into it. it is not recommended but you can give it a try. Here is a YouTube video that explains it.