Anti-Xray can be configured per world in the paper.yml configuration file. To understand how per world configuration works please read this[1] first. Note that after changing any settings for Anti-Xray you have to restart your server. Executing the /reload command (you should never do this) won't apply the settings to worlds that are already loaded.
The official documentation for the Anti-Xray settings and what they mean can be found here.
Basically Anti-Xray has two different modes. engine-mode: 1 replaces specified ores by "fake" stone, netherrack or end stone blocks depending on the world type and engine-mode: 2 randomly places specified fake ores when a chunk packet is sent to the client. The following