Issue on tutorial example - Add layer to map

Hi!,

Try to explore workflow SDK, can someone provide me a working code for the below tutorial?

https://developers.geocortex.com/docs/workflow/tutorial-web-add-layer-to-map/

It seems the AppActivity.map has an issue. The error in the console was react_devtools_backend.js:3973 TypeError: Cannot read properties of undefined (reading 'add')    at AddLayerToMap.eval (AddLayerToMap.ts?49d0:34:27). 

Thank you in advance

Charlie