How to downgrade from laravel 9.2 to laravel 8? – Shopify

I wanted to use the the

composer require osiset/laravel-shopify

but the issue is I’m running in laravel 8, I wanted to downgrade my laravel 9.2 to laravel 8.0 but when I tried downgrading it by changing the composer.json into

{
    "name": "laravel/laravel",
    "type": "project",
    "description": "The Laravel Framework.",
    "keywords": [
        "framework",
        "laravel"
    ],
    "license": "MIT",
    "require": {
        "php": "^7.3|^8.0",
        "fideloper/proxy": "^4.4.1",
        "fruitcake/laravel-cors": "^2.0.3",
        "guzzlehttp/guzzle": "^7.0.1",
        "laravel/framework": "^8.0",
        "laravel/passport": "^10.0",
        "laravel/tinker": "^2.5|dev-develop",
        "paragonie/random_compat": "2.*"
    },
    "require-dev": {
        "fakerphp/faker": "^1.9.1",
        "mockery/mockery": "^1.4.2",
        "nunomaduro/collision": "^5.0",
        "phpunit/phpunit": "^9.3.3"
    },
    "config": {
        "optimize-autoloader": true,
        "preferred-install": "dist",
        "sort-packages": true
    },
    "extra": {
        "laravel": {
            "dont-discover": []
        }
    },
    "autoload": {
        "psr-4": {
            "App\": "app/",
            "Database\Factories\": "database/factories/",
            "Database\Seeders\": "database/seeders/"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "Tests\": "tests/"
        }
    },
    "minimum-stability": "dev",
    "prefer-stable": true,
    "scripts": {
        "post-autoload-dump": [
            "Illuminate\Foundation\ComposerScripts::postAutoloadDump",
            "@php artisan package:discover --ansi"
        ],
        "post-root-package-install": [
            "@php -r "file_exists('.env') || copy('.env.example', '.env');""
        ],
        "post-create-project-cmd": [
            "@php artisan key:generate --ansi"
        ]
    }
}

but I’m getting these kind of errors

In Facade.php line 178:

Facade does not implement getFacadeAccessor method.

Script @php artisan package:discover –ansi handling the post-autoload-dump event returned with error code 1

I’m new to laravel and I don’t know what to do… thank you