Yes, the iPhone XR supports Qi standard wireless charging, so you can use Qi standard wireless charger to charge the iPhone XR wireless. The iPhone X also supports the Qi standard for wireless charging, so you can use the same Qi charger to charge both phones wirelessly.
It should be noted that when using wireless charging, a certain distance needs to be maintained between the phone and the charger, and the back of the phone needs to be aligned with the charger, otherwise it may affect the charging effect. Also, if you use a case on the iPhone X, you may need to remove the case in order to charge it wirelessly.
The iPhone XR can't charge the iPhone X wirelessly, because it doesn't have the function of reverse charging.