Laravel .env config DB_HOST 127.0.0.1 or mysql - laravel-9

Question

After starting a project (Laravel with Docker) according to https://laravel.com/docs/9.x/installation#getting-started-on-windows
There is a problem with DB_HOST in .env:
To perform artisan commands like php artisan migrate:fresh DB_HOST need to be set to 127.0.0.1 or localhost which makes sense to me.
But when displaying information on browser (localhost) DB_HOST need to be mysql, otherwise connection is refused.
Why would DB_HOST be set to mysql at all? How could I solve it so DB_HOST work for both cases?
.env
DB_CONNECTION=mysql
DB_HOST=127.0.0.1 || localhost || mysql(?)
DB_PORT=3306
B_DATABASE=tutorial
DB_USERNAME=sail
DB_PASSWORD=password
Database
'mysql' => [
'driver' => 'mysql',
'url' => env('DATABASE_URL'),
'host' => env('DB_HOST', '127.0.0.1'),
'port' => env('DB_PORT', '3306'),
'database' => env('DB_DATABASE', 'forge'),
'username' => env('DB_USERNAME', 'forge'),
'password' => env('DB_PASSWORD', ''),
'unix_socket' => env('DB_SOCKET', ''),
'charset' => 'utf8mb4',
'collation' => 'utf8mb4_unicode_ci',
'prefix' => '',
'prefix_indexes' => true,
'strict' => true,
'engine' => null,
'options' => extension_loaded('pdo_mysql') ? array_filter([
PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
]) : [],
],

Answer 1

For me, the solution was to find the docker IP with:
dd(Request::ip());
That was not 127.0.0.1 but 172.18.0.1.
After that I configured .ENV file with:
DB_HOST=172.18.0.1
And run
php artisan migrate:refresh
from docker terminal(and NOT from local) and everything works OK
Unfortunately, I don't know how to explain why, I hope someone else can shed a little more light on the matter