I lost my iphone X

If you lose your iPhone, iPad, or iPod touch or think it might be stolen, these steps might help you locate it and protect your data.

https://support.apple.com/en-us/HT201472

File a police report. In case a good samaritan finds it, they can get it back to you.

Here's Apple's suggestions: If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support