Vaadin Components don't work in IE11

I tried steps from this tutorial
And it doesn’t work in IE11.



As you can see - there is arrow function in result code which are unsupported by IE11.
However, article clearly states that “You are now ready to use web components in IE11+ and any of the evergreen browsers.”

My project is attached (but it’s the same as described in tutorial)

Initially, I tried to use combobox in my real application, but faces the same error - @webcombonents dependencies from node_modules aren’t transpilled.
I spent a lot of time trying to solve it (using both parcel and webpack) but without any success.
any suggestions? (56.3 KB)