What is the error when installing yii2?

Question

Yii

Hello! When installing yii2, instead of the welcome page, a folder tree pops up. Tell me, what could be wrong?

Answer 1

It looks like you have installed the advanced application template. It has two applications: backend, frontend. Inside each of these folders there should be a web folder, and in it an index.php file. The web server must be properly configured to interpret the index page.
https://github.com/yiisoft/yii2-app-advanced/blob/...
see point 4 under Preparing application