Answers for "insert a column in laravel 8"

Model class django.contrib.sites.models.Site doesn't declare an explicit app_label and isn't in an application in INSTALLED_APPS

Just add 'django.contrib.sites', to INSTALLED_APPS and set SITE_ID = 1 in your settings.py file.

laravel migration add column to existing table

php artisan make:migration add_paid_to_users_table --table=users
  
public function up()
{
    Schema::table('users', function($table) {
        $table->integer('paid');
    });
}

public function down()
{
    Schema::table('users', function($table) {
        $table->dropColumn('paid');
    });
}

php artisan migrate