D2 Compilation Error: err: failed to compile -: multiboard output cannot be written to stdout

[kcmvp]

runs into error with below, which is from https://d2lang.com/tour/steps/

d2 version: v0.6.9

Chicken's plan: {
  style.font-size: 35
  near: top-center
  shape: text
}

steps: {
  1: {
    Approach road
  }
  2: {
    Approach road -> Cross road
  }
  3: {
    Cross road -> Make you wonder why
  }
}