Inky:bit does not react

My Inky:bit arrived this week, and I tried it out using makecode.microbit.org.

basic.showIcon(IconNames.SmallHeart)
inkybit.drawText("Hello World", 56, 101, inkybit.Color.Black, inkybit.TextSize.Medium)
inkybit.drawRectangle(20, 110, 19, 19, inkybit.Color.Accent, false)
inkybit.show()
basic.showIcon(IconNames.Heart)

The code runs on the micro:bit (I have v2) just fine. After starting a smallHeart shows in the microbit display, and then about a second later the big heart. However, the inky:bit does not react, even after a few minutes nothing has changed on the inky:bit display.

What can I do to confirm that my inky:bit is working?