bmx fork?

I assume the key element you're after is the plate style dropouts mounted to the front edge of the fork legs. The closest I can get to representing this style of fork would be to choose the mountain bike fork option. Note you can uncheck the Suspension option in these forks to get something pretty representative of a BMX fork. I've done this to the forks on one of the models you submitted to the Design archive. The link is at: bikecad.ca/1535934905136.

Here's how it looks: