Execute this command in your terminal

composer require fjerbi/ultimate-admin-bundle

Add these lines in your services.yaml

 fjerbi\AdminBundle\Controller\AdminController:
calls:
- method: setContainer
arguments: [ '@service_container' ]

Add this in your routes.yaml

admin:
resource: '@Admin/Controller/'
type: annotation
prefix: /admin 

And finally execute this command

php bin/console doctrine:schema:update --force

check your database if the new tables were added successfully

NOTES: if you want to check the routes just execute this command

php bin/console debug:router

What's included ?