To run an application, use composer script:

composer install
composer serve

This will launch the php built-in web server.

If you are using docker, run the command:

docker-compose -p psr-framework up --build

The application will be available at http://127.0.0.1:8000

For development mode before build image you need add docker-compose.override.yml file.
Just copy the file docker-compose.override.yml.dist:

docker-compose.override.yml.dist -> docker-compose.override.yml

To use xdebug, set the settings in the file: .docker/php/conf.d/xdebug.ini