MTB none suspension forks 29"

Although there are lots of beefy non-suspension carbon forks for mountain bikes that can be well represented by the first style of fork in the fork dialog box, I assume you are looking for a fork more in the style of a suspension fork, just with rigid legs. Below is a screen shot from the free online version of BikeCAD where you can see the option to uncheck Suspension which will result in a rigid fork.

When the Suspension checkbox is unchecked, the lowers will be removed from the forks. This seems like the crucial differentiator between suspension and non-suspension forks. You've pointed out that the top caps are still there. While a non-suspension fork would not have a need for compression adjustment, those top caps don't necessarily have to represent a tuning knob. You can change the color to match that of the fork legs, or set dimension F to zero to eliminate the caps all together.