How to get origin URL on Deno Deploy?

What's the right way to get the origin URL

https://user-repo.deno.dev

https://user-repo.deno.dev

https://user-repo.deno.dev

https://user-repo.deno.dev in a Deno Deploy worker?

I could hardcode it, but would need to keep it in sync with a custom domain, etc. It seems

globalThis.location

globalThis.location

globalThis.location

globalThis.location isn't set on Deploy!?