Where is "Generate Terrian Texture" dialog box?

Hi All. I’m learning with
Following the Tutorial, I New a Level, but then I see a warning box. And, I don’t see the “Generate Terrian Texture”. I find a “Legacy Terrian” in Level Inspector, which makes my Perspective looks like that in the Tutorial, but I don’t know if theres something wrong hidden.


To generate terrrain just look at the top of this, it says Generate Terrain. Hope this helps.

Thank you. It really works. Thank you very much.