Vaadin Components don't work in IE11

Hi,
I tried steps from this tutorial
https://vaadin.com/tutorials/using-web-components
And it doesn’t work in IE11.

[https://ibb.co/HYpChjs]
(https://ibb.co/HYpChjs)

[https://ibb.co/N7TTMjg]
(https://ibb.co/N7TTMjg)

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?
17801584.zip (56.3 KB)