I assume that this happens because my company’s network setting prevents ngrok from working correctly, but I am not sure.
Do you have any idea to fix the situation?
Or, are there any ways to develop apps on local environment only?
Hey!
Yes, it looks like ngrok cannot create a tunnel because it is blocked by the firewall.
In general, we are using ngrok as a default method for having a preview for your app, because it provides secure https public tunnel to your localhost environment.
But actually, you can also work with your local environment directly without ngrok. Put to the preview View URL field in the feature preview mode the url to your localhost environment, f.e.: http://localhost:8301.
When you will switch to the preview mode, the iFrame will not work because of insecure/mixed content (monday website is working over the https, but your local environment is over http). To make it work, you should allow browser to display mixed/insecure content on this website.
You can find the way how to do it in chrome here: How to enable mixed content in my browser | Adobe Target