No "build command" section in Deno Deploy project settings

[AFGarrison]

I have a Deno Deploy project that I want to shift into using an ahead-of-time build due to one of my islands being very Javascript heavy. Initially I planned to do this through the Deno Deploy dashboard with the deno task build command, but the "build command" section mentioned in the documentation doesn't seem to exist on my screen.

In addition, I'm confused on how to set up an ahead of time build manually. The documentation says that the _fresh directory shouldn't be commited to the repository, but I'm not sure how to pass the build to Deno Deploy otherwise. Can I update the rest of the project as is and only refrain from adding the _fresh repository, or do I need to upload the directory to GitHub in such a way that it is ignored on deployment?