How to build and package CommandApp from decline library

Question

(Note: I'm totally new to Scala and still wrapping my head around sbt tooling)

I have a small command line app using decline and I am confused about how to build it so as to execute that from console.

I referred the quick-start tutorial for decline - https://ben.kirw.in/decline/ that has below example.

import cats.implicits._
import com.monovore.decline._

object HelloWorld extends CommandApp(
  name = "hello-world",
  header = "Says hello!",
  main = {
    val userOpt =
      Opts.option[String]("target", help = "Person to greet.").withDefault("world")

    val quietOpt = Opts.flag("quiet", help = "Whether to be quiet.").orFalse

    (userOpt, quietOpt).mapN { (user, quiet) =>
      if (quiet) println("...")
      else println(s"Hello $user!")
    }
  }
)

And it shows the resulting app can be executed from console like below.

$ hello-world --help
Usage: hello-world [--target <string>] [--quiet]

Says hello!

Options and flags:
    --help
        Display this help text.
    --target <string>
        Person to greet.
    --quiet
        Whether to be quiet.

$ hello-world --target friend
Hello, friend!

Could someone please guide me how to build the source code to have this executable app? I have read through sbt tasks but could not find anything that works.

Appreciate any pointers on this.