Development template issue on bin/

Hi all,

I get this error when running bin/watch-administration command, do you have any hint?

> administration@1.0.0 dev
> mode=development webpack-dev-server

# Compiling with Webpack configuration
# Development mode is activated 🛠
BaseUrl for proxy is set to "undefined"

 ⚠️  You need to add the "APP_URL" as an environment variable for compiling the code.

I reply to myself:

edited, added this line

export APP_URL

edited .env file, added this line