No consigo ejecutar un alert o un promt

Buenas tardes.
Cuando utilizo la extensión KI04_CreateWebView para visualizar un archivo html no consigo que se ejecuten un alert o un promt. No sé si debo de configurar algo.

Please provide a more detailed explanation of what you are trying to achieve,
what you have done so far, what works, what doesn't work...

Please show your relevant blocks,
if relevant, your data or lists,
screenshots of the Designer screen or app in action,
so we can see what you are trying to do...

Right Click in Blocks Editor and select "Download Blocks as Image"
for the best image of your blocks.

Try with CustumWebView extension.