How to use the extended function GY-521

Even if you enter the sample code in “main.ts” of JavaScript of MakeCode, there is a problem in “microbit_GY521.initialise();” of the extension function GY-521 and it cannot be programmed in the microbit.
Please tell me how to resolve.

https://makecode.microbit.org/pkg/pauldfoster/pxt-microbit-gy521