It’s off by default, but activated when you end your search query with a question mark. That option can be turned off.

That’s not as effective, since it can’t block anything that’s hosted from a hostname that also serves regular content without also blocking the regular content. It also can’t trick websites into thinking that nothing is blocked and it can’t apply cosmetic rules. I use it for my devices, but in browsers I supplement it with uBlock Origin (or whatever is available in that browser).