Laravel Passport Setup and Installation Steps

OAuth-2 Setup & Installation

STEP 1: php artisn make:auth

STEP 2: composer require  laravel/passport

STEP 3: php artisan migrate

STEP 4: php artisan passport:install

STEP 5: use HasApiTokens Trait in User Model.

STEP 6: Add Passport::routes(); to boot() method of RouteServiceProvider Class

STEP 7: Change api driver('token') to 'passport' in config => auth.php

STEP 8: Install a new Laravel instance for client-server(Server which which is asking for authorization from us)

STEP 9: Install the guzzel package on client-server ( composer require guzzlehttp/guzzle )

STEP 10: Run php artisan passport:client command on your original application 
      
         - Enter user ID which you got by running passport:install command (in STEP 4)
         - Enter the name of the client anything ( Client Server)
         - Redirect after authorization  (http://127.0.0.1:8001/callback)
      
STEP 11: Copy the generated Client ID and Client Secret

STEP 12: In client-server installation => web.php file put the following code & replace the client ID and Secret with the 
         values copied in STEP 11.

            Route::get('/redirect', function () {

                $query = http_build_query([
                    'client_id' => '3',
                    'redirect_uri' => 'http://127.0.0.1:8001/callback',
                    'response_type' => 'code',
                    'scope' => ''
                ]);

                return redirect('http://127.0.0.1:8000/oauth/authorize?'.$query);
            });

            Route::get('/callback', function (Illuminate\Http\Request $request) {
                $http = new \GuzzleHttp\Client;

                $response = $http->post('http://127.0.0.1:8000/oauth/token', [
                    'form_params' => [
                        'client_id' => '3',
                        'client_secret' => 'fdFaiBUBjDmLoKiBmFpuTvLyAXyoCuusAvJljBQF',
                        'grant_type' => 'authorization_code',
                        'redirect_uri' => 'http://127.0.0.1:8001/callback',
                        'code' => $request->code,
                    ],
                ]);
                return json_decode((string) $response->getBody(), true);
            });

STEP 13: Go to your orignal application => Kernel.php => middlewaregroups => api => 'auth:api'

STEP 14: Run both the applications & visit https://127.0.0.1:8001/redirect
          
STEP 11: Client-server will redirect us to our orignal website from where we have to login and authorize the app.

STEP 12: After successfull authorization it will redirect back to client-server with 'access_token', 'token_type', 'refresh_token'. 
         client can use access_token to get access to the underlying data.