Open command line and "composer require paragonie/random_compat=~2.0" run this command

After setup random compat

Install laravel passport composer require laravel/passport

After install

run this command "php artisan migrate"
 

Then define passport in config/app.php file 

Like as  

add this code in provider section

Laravel\Passport\PassportServiceProvider::class,

Then run command

php artisan passport:install

Now we get 2 client id & encryption key

After running this command, add the "Laravel\Passport\HasApiTokens" trait to your App\User model. 

add this ato top in controller

"use Laravel\Passport\HasApiTokens;"

add this in class in controller

"use HasApiTokens, Notifiable;"

Next, you should call the Passport::routes method within the boot method of your AuthServiceProvider.

Then open the file "AuthServiceProvider.php" in Providers folder 

add "use Laravel\Passport\Passport;" it top

and 

public function boot(){

      $this->registerPolicies();

      Passport::routes();

    }

Finally, in your config/auth.php configuration file, you should set the driver option of the api authentication guard to passport.

api driver changed to passport

 'api' => [

            'driver' => 'token',

            'provider' => 'users',

            'hash' => false,

        ],

After implements passport add a middleware in the routes which provide apis (routes/api.php)

Route::middleware(['auth:api'])->group(function () {

    Route::apiResource('services','Api\ServiceController');

});

Token Lifetimes

public function boot(){

        $this->registerPolicies();

        Passport::routes();

        Passport::tokensExpireIn(now()->addDays(15));

        Passport::refreshTokensExpireIn(now()->addDays(30));

    }

Then run the passport client 

 php artisan passport:client (give user id)

get Client secret 

get the access token (in postman)

first set the client at body/form-data in postman and set data

grant_type = client_redentials

client_id = 1

client_secret =Client secret

localhost/project/oauth/token (post)